Physics

Determination of length and position of an object which cannot be seen

PrincipleThis experiment provides training in determining the length and position of an object based on an X-ray image. A metal pin that is embedded in a wooden block is used as the model. This experiment is also an excellent preparatory exercise for demonstrating the principle of computed tomography. Benefits Simulation of a real-life situation in […]

Contrast medium experiment with a blood vessel model

PrincipleWhen a blood vessel model is irradiated with X-rays, the blood vessels themselves are not visible at first. It is only after the injection of a contrast medium that the blood vessels become visible. Tasks Inject a 50% potassium iodide solution into the blood vessel model. Observe the fluorescent screen of the X-ray basic unit […]

Radiographic examination of objects

Principle An X-ray tube produces X-rays that cause a fluorescent screen to emit light. Objects that are located between the X-ray source and the fluorescent screen will be irradiated so that their inner structure becomes visible. If one varies the anode current and voltage, the change in intensity can be observed in a qualitative manner […]

Characteristic X-ray lines of different anode materials / Moseley’s law

Principle Moseley’s law describes the relationship between the energy of the Ka lines of characteristic X-ray spectra and the atomic number. In this experiment, the characteristic X-ray lines of various different anode materials are determined in order to verify Moseley’s law. Tasks Record the X-ray spectra of the three X-ray tubes. Determine the wavelengths and […]

Duane-Hunt displacement law and Planck’s “quantum of action”

Principle X-ray spectra are recorded as a function of the anode voltage. The short wavelength limit of the bremsspectrum is used to determine the agreement with the Duane-Hunt displacement law, and to determine Planck’s “quantum of action”. Tasks Record the intensity of the X-rays emitted by the copper anode at various anode voltages as a […]

K alpha doublet splitting of iron X-rays / fine structure

PrincipleThe polychromatic iron X-ray spectrum is to analyzed by means of a monocrystal. The energy of the characteristic lines is to be determined from the positions of the glancing angles for various orders of diffraction. The separation of the Ka doublet in higher order diffraction is to be examined. Tasks Record the intensity of the […]

K alpha double splitting of molybdenum X-rays / fine structure

Principle The polychromatic molybdenum X-ray spectrum is analyzed by means of a monocrystal. The energy of the characteristic lines is determined from the positions of the glancing angles at various orders of diffraction. The separation of the K a doublet in higher order diffraction is examined. Tasks Record the intensity of the X-rays emitted by the molybdenum […]

Monochromatisation of copper X-rays

Principle The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils. Tasks Record the intensity of the X-rays emitted by the copper anode as a […]

Monochromatisation of molybdenum X-rays

Principle The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils. Tasks Record the intensity of the X-rays emitted by the molybdenum anode as a […]

Monochromatisation of molybdenum X-rays

Principle The X-rays that are generated by an X-ray tube are polychromatic. Numerous experiments (e.g. Debye-Scherrer experiments concerning crystal structures), however, require monochromatic X-radiation, which can be generated by filtering the X-rays with monocrystals or with the aid of metal foils. Tasks Record the intensity of the X-rays emitted by the molybdenum anode as a […]

The intensity of characteristic X-rays as a function of the anode current and anode voltage

Principle The polychromatic X-radiation from a copper anode is analyzed using a LiF monocrystal according to Bragg. Varying the anode current and anode voltage influences the intensity of the characteristic K a and K b radiation. Tasks Record the intensity spectrum of polychromatic radiation from a X-ray tube with the help of a LiF monocrystal. Determine the intensities of the characteristic K a and K b radiations […]

Characteristic X-rays of tungsten

Principle An X-ray tube with a tungsten anode generates X-radiation that is selected with the aid of a monocrystal as a function of the Bragg angle. A Geiger-Müller counter tube measures the intensity of the radiation. The glancing angles of the characteristic X-ray lines are then used to determine the energy. Tasks Record the intensity […]

Characteristic X-rays of iron

Principle Spectra of X-rays from an iron anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction Tasks Record the intensity of the X-rays emitted by the […]

Characteristic X-rays of molybdenum

Principle Spectra of X-rays from a molybdenum anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the […]

Characteristic X-rays of copper

Principle Spectra of X-rays from a copper anode are analyzed using different monocrystals and the results plotted graphically. The energies of the characteristic lines are then determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the copper anode as a function of the […]

Fourier optics – 2f arrangement

PrincipleThe electric field distribution of light in a specific plane (object plane) is Fourier transformed into the 2 f configuration. Tasks Investigation of the Fourier transform by a convex lens for different diffraction objects in a 2 f setup. What you can learn about Fourier transform Lenses Fraunhofer diffraction Index of refraction Huygens’ principle  Scope […]

Magnetostriction with the Michelson interferometer

PrincipleWith the aid of two mirrors in a Michelson arrangement, light is brought to interference. Due to the magnetostrictive effect, one of the mirrors is shifted by variation in the magnetic field applied to a sample and the change in the interference pattern is observed. Benefits See that magnetic fields can change the geometry of […]

Michelson interferometer – High Resolution

Principle With the aid of two mirrors in a Michelson arrangement, light is brought to interference. While moving one of the mirrors, the alterationin the interference pattern is observed and the wave length of the laser light determined. Benefits Learn about the measurement principle with which gravitational waves can be observed Assemble your own interferometer using invidual optical components […]

Quantum eraser with the Mach-Zehnder interferometer

Principle A Mach-Zehnder-interferometer is illuminated with a laser beam. Circular interference fringes appear on the screens behind the interferometer. If polarisation filters with opposite polarisation planes are placed in the two interferometer paths the interference patterns disappear. Placing another polariser before one of the screens causes the pattern to reappear. Electromagnetic radiation can be described […]

Coherence and width of spectral lines with the Michelson interferometer

Principle The wavelengths and the corresponding lengths of coherence of the green spectral lines of an extreme high pressure Hg vapour lamp are determined by means of a Michelson interferometer. Different double slit combinations are illuminated to verify the coherence conditions of non punctual light sources. An illuminated auxiliary adjustable slit acts as a non […]

Fibre optics

Principle The beam of a laser diode is treated in a way that it can be coupled into a monomode fibre. The problems related to coupling the beam into the fibre are evaluated and verified. In consequence a low frequency signal is transmitted through the fibre. The numerical aperture of the fibre is recorded. The […]

Nd:YAG laser

Principle The rate equation model for an optically pumped four-level laser system is determined. As lasing medium, a Nd:YAG (Neodymium-Yttrium Aluminium Garnet) rod has been selected which is pumped by means of a semiconductor diode laser. The IR-power output of the Nd:YAG laser is measured as a function of the optical power input and the […]

Helium Neon laser, basic set

Principle The difference between spontaneous and stimulated emission of light is demonstrated. The beam propagation within the resonator cavity of a He-Ne laser and its divergence are determined, its stability criterion is checked and the relative output power of the laser is measured as a function of the tube’s position inside the resonator and of […]

Recording and reconstruction of holograms with the optical base plate

Principle In contrast to normal photography a hologram can store information about the three-dimensionality of an object. To capture the three-dimensionality of an object, the film stores not only the amplitude but also the phase of the light rays. To achieve this, a coherent light beam (laser light) is split into an object and a […]

Fabry-Perot interferometer – optical resonator modes

Principle Two mirrors are assembled to form a Fabry-Perot interferometer. Using them, the multibeam interference ofa laser’s light beam is investigated.On moving one of the mirrors, thechange in the intensity distributionof the interfeence pattern is studied. This is a qualitative experiment,to study the shape of different lasermodes and compare it with some photosgiven in this […]

Visualisation of radioactive particles/ diffusion cloud chamber

Principle Radioactivity is a subject in our society which has been playing an important role throughout politics, economy and media for many years now. The fact that this radiation cannot be seen or felt by the human being and that the effects of this radiation are still not fully explored yet, causes emotions like no […]

X-ray dosimetry

Principle Dosimetry, as a subspecialty of medical physics, deals with the determination and calculation of dose rates, which is also of great importance in view of the radiation protection directives. This experiment demonstrates the principle of measurement and it explains the various units of absorbed dose, equivalent dose, and absorbed dose rate. Inside a plate […]

Counter tube characteristics

Principle The counter tube uses the ionising effect of high-energy radiation in order to measure the intensity of the radiation. The counter tube characteristics describe its working range, i.e. the voltage range in which it reliably counts the incoming particles. Tasks Determine the counter tube characteristics of the type B counter tube that is used. […]

Photonuclear cross-section / Compton scattering cross-section

Principle The radiation of 137Cs and 22Na is measured with a scintillation detector and the energy spectrum determined with a multi channel analyzer. The fractions of the spectra caused by Compton scattering and those caused by the photoelectric effect are determined on the basis of their areas. The results are used for determining the ratio of the effective cross-sections and examining […]

Internal conversion in 137m Ba with MCA

Principle The radiation emitted during the decay of the 137Cs isotope is measured with a scintillation detector and the energyspectrum determined with a pulse height analyzer. The spectrum contains fractions due to a gamma-transition and fractions originating from a characteristic X-ray radiation. The areas of the fractions in question are determined and the conversion factor obtained from […]

Energy dependence of the gamma absorption coefficient / Gamma spectroscopy

Principle The intensity of gamma-radiation decreases when it passes through solid matter. The attenuation can be the result of Compton scattering, the photo effect or the pair production. An absorption coefficient can be attributed to each of the three phenomena. These absorption coefficients, as well as the total absorption, are highly energy-dependent. The energy dependence […]

Inverse-square law and absorption of gamma or beta rays with the Geiger-Müller counter

Principle The inverse square law of distance is demonstrated with the gamma radiation from a 60-Co preparation, the half-value thickness and absorption coefficient of various materials determined with the narrow beam system and the corresponding mass attenuation coefficient calculated. Tasks To measure the impulse counting rate as a function of the distance between the source […]

Beta spectroscopy

Principle The radiation of β-unstable atomic nuclei is selected on the basis of its pulses in a magnetic transverse field, using a diaphragm system. The relationship between coil current and particle energy is determined for calibration of the spectrometer and the decay energy of the β-transition is obtained in each case from the β–-spectra. Tasks […]

Electron absorption

Principle The attenuation of an electron particle stream passing through a material layer depends both on the thickness of the layer and on the mass coverage, resp. the “mass per unit area”. It will be shown that the particle flux consisting of electrons of a particular energy distribution decreases with the “mass per unit area”. […]

Energy loss of alpha particles in gases with MCA

Principle A study is made of the connection between the energy E of alpha-particles and the path x travelled by them in air at standard pressure. The measurements recorded enable the differencial energy loss dE/dx to be calculated as a function of x. Tasks The spectrum of a covered 241Am source is measured at a fixed distance […]

Study of the alpha energies of Ra-226 with MCA

Principle An alpha-spectrometer, consisting of a silicon surface barrier layer detector, a preamplifier, a pulse height analyser and a recording device for registration of the spectra is calibrated by means of an open alpha-emitter of known alpha-energy (241Am). The energy spectrum of a radium source which is in equilibrium with its decay products, is recorded […]

Fine structure of the alpha spectrum of Am-241 with MCA/ alpha spectroscopy

Principle The alpha-spectrum of an open 241Am-emitter is measured with a semiconductor a-detector. In connection with a multi channel analyzer the main parts of the spectrum are investigated. Tasks The spectrum of an uncovered 241Am-emitter is recorded with the multi channel analyzer. The energies of the two peaks preceding the principal peak are calculated. The principal peak, corresponding […]

Rutherford experiment with MCA

Principle The relationship between the angle of scattering and the rate of scattering of alpha-particles by gold foil is examined with a semiconductor detector. This detector has a detection probability of 1 for alpha-particles and virtually no zero effect, so that the number of pulses agrees exactly with the number of alpha-particles striking the detector. […]

Alpha energies of different sources with MCA

Principle An alpha-spectrometer, consisting of a photodetector, a preamplifier, a pulse height analyser and a recording device for registration of the spectra is calibrated by means of an open alpha-emitter of known alpha energy (241Am). The energy spectrum of a radium source which is in equilibrium with its decay products, is recorded and evaluated. The […]

Visualisation of radioactive particles/ diffusion cloud chamber

Principle Radioactivity is a subject in our society which has been playing an important role throughout politics, economy and media for many years now. The fact that this radiation cannot be seen or felt by the human being and that the effects of this radiation are still not fully explored yet, causes emotions like no […]

Poisson’s and Gaussian distribution of radioactive decay with Cobra4 (Influence of the dead time of the counter tube

Principle 1) The aim of this experiment is to show that the number of pulses counted during identical time intervals by a counter tube which bears a fixed distance to along-lived radiation emitter correspond to a Poisson´s distribution. A special characteristic of the Poisson´s distribution can be observed in the case of a small number […]

Half-life and radioactive equilibrium

Principle The half-life of a Ba-137 m daughter substance eluted (washed) out of a Cs-137 isotope generator is measured directly and is also determined from the increase in activity after elution. Tasks To measure the activity of the isotope generator as a function of time immediately after elution. To measure the activity of a freshly […]

Atomic Resolution of the graphite surface by STM (Scanning Tunneling Microscope)

Principle Approaching a very sharp metal tip to an electrically conductive sample by applying a electrical field leads to a current between tip and sample without any mechanical contact. This so-called tunneling current is used to investigate the electronic topography on the sub nanometer scale of a fresh prepared graphite (HOPG) surface. By scanning the […]

Basic methods in imaging of micro and nanostructures with AFM (Atomic Force Microscopy)

Principle Approaching a sharp silicon tip mounted on a cantilever to a sample surface leads to an atomic scale interaction. The result is a bend of the cantilever which is detected by a laser. In static mode the resulting deflection is used to investigate the topography of the sample surface line by line using a […]

Band gap of germanium

Prinzip Die Leitfähigkeit einer undotierten Germanium-Probe wird in Abhängigkeit von der Temperatur gemessen. Die Energielücke wird aus den gemessenen Werten bestimmt. Vorteile Die PHYWE Hall Effekt Unit kann auch für Messungen mit n- und p- dotiertem Germanium verwendet werden Einfacher Versuchsaufbau Auch für SEK II geeignet Aufgaben Der Strom und die Spannung werden in einer […]

Hall effect in n- and p-germanium (Teslameter)

Principle The resistivity and Hall voltage of 2  rectangular germanium samples ( n- and p-) are measured as a function of temperature and magnetic field. The band spacing, the specific conductivity, the type of charge carrier and the mobility of the charge carriers are determined from the measurements. Tasks The Hall voltage is measured at room temperature […]

Atomic Resolution of the graphite surface by STM (Scanning Tunneling Microscope)

Principle Approaching a very sharp metal tip to an electrically conductive sample by applying a electrical field leads to a current between tip and sample without any mechanical contact. This so-called tunneling current is used to investigate the electronic topography on the sub nanometer scale of a fresh prepared graphite (HOPG) surface. By scanning the […]

Magnetostriction with the Michelson interferometer

PrincipleWith the aid of two mirrors in a Michelson arrangement, light is brought to interference. Due to the magnetostrictive effect, one of the mirrors is shifted by variation in the magnetic field applied to a sample and the change in the interference pattern is observed. Benefits See that magnetic fields can change the geometry of […]

Ferromagnetic hysteresis with Cobra4

Principle A magnetic field is generated in a ring-shaped iron core by a continuous adjustable direct current applied to two coils. The field strength Η and the flux density B are measured and the hysteresis recorded. The remanence and the coercive field strength of two different iron cores can be compared. Benefits Simple experimental setup and intuitive handling of […]

Dielectric constant of different materials

PrincipleThe electric constant is determined by measuring the charge of a plate capacitor to which a voltage is applied. The dielectric constant is determined in the same way, with plastic or glass filling the space between the plates. Benefits Supplies non-hazardous high voltage Easy experimental set-up due to clear and compact design Clever investment: The […]

Characteristic curves of semiconductors with Cobra4 Xpert-Link

Principle Determine the current strength flowing through a semi-conducting diode. Determine the collector current with the collector voltage for various values of the base current intensity. Benefits Fast and easy experimenting Get to know the behaviour of several types of semiconductors Detailed experiment guide with extensive explanations and step-by-step instructions Measure voltage and current simultaneously […]

Characteristic curves of semiconductors with Cobra4

PrincipleThe current-voltage characteristic of a semiconducting diode is measured. The collector current in dependency on the emitter-collector voltage is measured for different values of base current strength through a NPN transistor. Benefits Fast and easy experimenting Get to know the behaviour of several types of semiconductors Simplified implementation: all pre-settings already prepared Data logging reveals instantaneous […]

Characteristic curves of a solar cell

Principle The current-voltage characteristics of a solar cell are measured at different light intensities, the distance between the light source and the solar cell being varied. The dependence of no-load voltage and short-circuit current on temperature is determined. Benefits Set-up allows quantitative measurement which also takes light intensity into account Set-up allows to avoid but […]

Peltier heat pump

Principle The (cooling capacity) heating capacity and efficiency rating of a Peltier heat pump are determined under different operating conditions. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment setup can also be used for investigating the Seebeck effect Tasks To determine the […]

Nd:YAG laser

Principle The rate equation model for an optically pumped four-level laser system is determined. As lasing medium, a Nd:YAG (Neodymium-Yttrium Aluminium Garnet) rod has been selected which is pumped by means of a semiconductor diode laser. The IR-power output of the Nd:YAG laser is measured as a function of the optical power input and the […]

Mechanical hysteresis

Principle The relationship between torque and angle of rotation is determined when metal bars are twisted. The hysteresis curve is recorded. Benefits Beyond Hooke’s law Hysteresis – mostly known from the field of magnetism – can be experienced in mechanics Learn the meaning of the words stress, relaxation and equilibrium in a physics context Various […]

Modulus of elasticity / Youngs Modulus

Principle A flat bar is supported at two points. It is bent by the action of a force acting at its centre. The modulus of elasticity is determined from the bending and the geometric data of the bar. Benefits Find out the parameters that give a bar stability Measure the difference of elasticity in various […]

Velocity of ultrasound in solid state material

Principle The velocity of sound in acrylics shall be determined by time of flight reflection technique with an ultrasonic echoscope. The measurements are done by reflection method, on three cylinders of different length. Two measurement series are carried out with ultrasonic probes of different frequencies. Benefits Introductory experiment for echoscopy applications Experiment can be easily […]

Duane-Hunt displacement law

Principle X-ray spectra of an X-ray tube are measured in an energy dispersive manner with a semiconductor detector and with various anode voltages. Duane and Hunt’s  law of displacement is verified with the aid of the maximum energy of the bremsspectrum. Tasks Recording of the X-ray spectrum that is emitted by the copper anode for […]

Determination of the lattice constants of a monocrystal

Principle Polychromatic X-rays impinge on a monocrystal under various glancing angles. The rays are reflected by the lattice planes of the monocrystal. An energy detector is only used to measure those radiation parts that interfere constructively. The lattice constant of the crystal is determined with the aid of the various orders of diffraction and the […]

Energy-dispersive measurements of K- and L-absorption edges

Principle Thin powder samples are subjected to polychromatic X-rays. The energy of the radiation that passes through the samples is analysed with the aid of a semiconductor detector and a multi-channel analyser. The energy of the corresponding absorption edges is determined and the resulting Moseley diagrams are used to determine the Rydberg frequency, the screening […]

Debye-Scherrer diffraction patterns with a cubic powder sample

PrincipleA cubic crystalline powder sample is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice planes of the crystallites. The Bragg diagram is automatically recorded. A graphical evaluation procedure is used to assign […]

Debye-Scherrer diffraction patterns of powder samples with a tetragonal lattice structure

PrincipleA polycrystalline powder sample of lead dioxide is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice planes of the crystallites. The Debye-Scherrer pattern is automatically recorded. The evaluation of the pattern not […]

Debye-Scherrer diffraction patterns of powder samples with a hexagonal lattice structure

Principle A polycrystalline powder sample of zinc is irradiated with the radiation from a X-ray tube with a copper anode. A Geiger-Mueller counter tube is automatically swivelled to detect the radiation that is constructively reflected from the various lattice planes of the crystallites. The Debye-Scherrer pattern is automatically recorded. The evaluation of the pattern not […]

Debye-Scherrer diffractions pattern of powder samples with a diamond structure (according to Bragg-Brentano)

PrinciplePolycrystalline powder samples, which crystallize in the three cubic Bravais types, simple, face-centered and body-centered, are irradiated with the radiation from a Roentgen tube with a copper anode. A swivelling Geiger-Mueller counter tube detects the radiation that is constructively reflected from the various lattice planes of the crystallites. The Bragg diagrams are automatically recorded. Their […]

Debye-Scherrer diffraction patterns of powder samples with three cubic Bravais lattices

Principle Polycrystalline powder samples, which crystallize in the three cubic Bravais types, simple, face-centered and body-centered, are irradiated with the radiation from a Roentgen tube with a copper anode. A swivelling Geiger-Mueller counter tube detects the radiation that is constructively reflected from the various lattice planes of the crystallites. The Bragg diagrams are automatically recorded. […]

X-ray investigation of crystal structures / Laue method with digital X-ray image sensor(XRIS)

Principle Laue diagrams are produced when monocrystals are irradiated with polychromatic X-rays. This method is primarily used for the determination of crystal symmetries and the orientation of crystals. When a LiF monocrystal is irradiated with polychromatic X-rays, a characteristic diffraction pattern results. This pattern is photographed with the digital X-ray sensor XRIS. Tasks The Laue […]

X-ray investigation of hexagonal crystal structures / Debye-Scherrer powder method

Principle A polycrystalline zirconium foil is irradiated with X-rays. The resulting Debye-Scherrer reflections are photographed and then evaluated. Tasks Take Debye-Scherrer photographs of the zirconium sample. Evaluate the Debye-Scherrer rings and assign them to the corresponding lattice planes. Determine the lattice constants of the sample material. Determine the number of atoms in a unit cell […]

X-ray investigation of crystal structures / Laue method

Principle Laue diagrams are produced when monocrystals are irradiated with polychromatic X-rays. This method is primarily used for the determination of crystal symmetries and the orientation of crystals. When a LiF monocrystal is irradiated with polychromatic X-rays, a characteristic diffraction pattern results. This pattern is photographed and then evaluated. Tasks The Laue diffraction of an […]

X-ray investigation of cubic crystal structures / Debye-Scherrer powder method

Principle When polycrystalline samples are irradiated with X-rays a characteristic diffraction pattern results. These Debye-Scherrer reflections are photographed and then evaluated. Tasks Debye-Scherrer photographs are to be taken of powdered samples of sodium chloride and caesium chloride. The Debye-Scherrer rings are to be evaluated and assigned to the corresponding lattice planes. The lattice constants of […]

Examination of the structure of NaCl monocrystals with different orientations

Principle The spectra of the X-rays that are reflected with various different orientations by NaCl monocrystals are analysed. The associated interplanar spacings are determined based on the Bragg angles of the characteristic lines. Tasks Determine the intensity of the X-rays that are reflected by the NaCl monocrystals with the orientations [100], [110] and [111] as […]

Hall effect in n- and p-germanium (PC)

Principle The resistivity and Hall voltage of a rectangular germanium sample are measured as a function of temperature and magnetic field. The band spacing, the specific conductivity, the type of charge carrier and the mobility of the charge carriers are determined from the measurements. Tasks The Hall voltage is measured at room temperature and constant […]

Hall effect in metals

Principle The Hall effect in thin zinc and copper foils is studied and the Hall coefficient determined. The effect of temperature on the Hall voltage is investigated. Tasks The Hall voltage is measured in thin copper and zinc foils. The Hall coefficient is determined from measurements of the current and the magnetic induction. The temperature […]

Beta spectroscopy

Principle The radiation of β-unstable atomic nuclei is selected on the basis of its pulses in a magnetic transverse field, using a diaphragm system. The relationship between coil current and particle energy is determined for calibration of the spectrometer and the decay energy of the β-transition is obtained in each case from the β–-spectra. Tasks […]

Semiconductor thermogenerator – Seebeck effect

Principle In a semi-conductor thermogenerator, the no-load voltage and the short-circuit current are measured as a function of the temperature difference. The internal resistance, the Seebeck coefficient and the efficiency are determined. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment […]

Absorption spectra

PrincipleElectron shells of metal atoms in the gas phase can be elevated to an excited state by light. If light is passed through the metal vapour, various lines will be absent from its spectrum afterwards. These lines correspond to the energy levels of those electrons in the metal vapour which have been excited by the […]

Rutherford experiment with MCA

Principle The relationship between the angle of scattering and the rate of scattering of alpha-particles by gold foil is examined with a semiconductor detector. This detector has a detection probability of 1 for alpha-particles and virtually no zero effect, so that the number of pulses agrees exactly with the number of alpha-particles striking the detector. […]

Electron spin resonance

Principle With electron spin resonance (ESR) spectroscopy compounds having unpaired electrons can be studied. The physical background of ESR is similar to that of nuclear magnetic resonance (NMR), but with this technique electron spins are excited instead of spins of atomic nuclei. The g-factor of a DPPH (Diphenylpikrylhydrazyl) specimen and the halfwidth of the absorption line […]

Stern-Gerlach experiment

Principle A beam of potassium atoms generated in a hot furnace travels along a specific path in a magnetic two-wire field. Because of the magnetic moment of the potassium atoms, the non-homogeneity of the field applies a force at right angles to the direction of their motion. The potassium atoms are thereby deflected from their […]

Helium Neon laser, basic set

Principle The difference between spontaneous and stimulated emission of light is demonstrated. The beam propagation within the resonator cavity of a He-Ne laser and its divergence are determined, its stability criterion is checked and the relative output power of the laser is measured as a function of the tube’s position inside the resonator and of […]

K alpha doublet splitting of iron X-rays / fine structure

PrincipleThe polychromatic iron X-ray spectrum is to analyzed by means of a monocrystal. The energy of the characteristic lines is to be determined from the positions of the glancing angles for various orders of diffraction. The separation of the Ka doublet in higher order diffraction is to be examined. Tasks Record the intensity of the […]

K alpha double splitting of molybdenum X-rays / fine structure

Principle The polychromatic molybdenum X-ray spectrum is analyzed by means of a monocrystal. The energy of the characteristic lines is determined from the positions of the glancing angles at various orders of diffraction. The separation of the K a doublet in higher order diffraction is examined. Tasks Record the intensity of the X-rays emitted by the molybdenum […]

Characteristic X-rays of tungsten

Principle An X-ray tube with a tungsten anode generates X-radiation that is selected with the aid of a monocrystal as a function of the Bragg angle. A Geiger-Müller counter tube measures the intensity of the radiation. The glancing angles of the characteristic X-ray lines are then used to determine the energy. Tasks Record the intensity […]

Characteristic X-rays of iron

Principle Spectra of X-rays from an iron anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction Tasks Record the intensity of the X-rays emitted by the […]

Characteristic X-rays of molybdenum

Principle Spectra of X-rays from a molybdenum anode are to be analyzed by means of different monocrystals and the results plotted graphically. The energies of the characteristic lines are then to be determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the […]

Characteristic X-rays of copper

Principle Spectra of X-rays from a copper anode are analyzed using different monocrystals and the results plotted graphically. The energies of the characteristic lines are then determined from the positions of the glancing angles for the various orders of diffraction. Tasks Record the intensity of the X-rays emitted by the copper anode as a function of the […]

K and L absorption edges of X-rays / Moseley’s law and the Rydberg constant

Principle Samples of various elements of different atomic numbers are irradiated with X-rays of a known spectral distribution. The energy of the transmitted intensities is analyzed using a monocrystal analyzer. Subsequently, the Rydberg constant and the screening constants are calculated from the energy of the absorption edges. Tasks Record the intensity of the X-rays emitted […]

Characteristic X-ray lines of different anode materials / Moseley’s law

Principle Moseley’s law describes the relationship between the energy of the Ka lines of characteristic X-ray spectra and the atomic number. In this experiment, the characteristic X-ray lines of various different anode materials are determined in order to verify Moseley’s law. Tasks Record the X-ray spectra of the three X-ray tubes. Determine the wavelengths and […]

X-ray fluorescence and Moseley’s law

Principle The irradiation of iodine, barium (sulfat), silver and tin with soft gamma-radiations gives rise to Ka radiations characteristics of these elements. The X-ray spectra are recorded with a gamma spectrometer consisting of a scintillation counter, a pulse height analyser and a recorder. After calibration of the spectrometer, the Rydberg constant is determined from the energies […]

Atomic spectra of two-electron system: He, Hg

Principle The spectral lines of He and Hg are examined by means of a diffraction grating. The wavelengths of the lines are determined from the geometrical arrangement and the diffraction grating constants. Tasks Determination of the wavelengths of the most intense spectral lines of He. Determination of the wavelengths of the most intense spectral lines […]

Fundamental principles of Nuclear Magnetic Resonance (NMR)

Principle The fundamental principles concerning the phenomenon of nuclear magnetic resonance (NMR) are demonstrated. Experiments are executed with a MRT training device giving the opportunity to investigate some small probes in the sample chamber. Investigations comprise the tuning of the system frequency to the Larmor frequency, the determination of the flip angle of the magnetisation vector, the […]

https://www.phywe.com/en/zeeman-effect-with-a-variable-magnetic-system.html

Principle The “Zeeman effect” is the splitting up of the spectral lines of atoms within a magnetic field. The simplest is the splitting up of one spectral line into three components called the “normal Zeeman effect”. In this experiment the normal Zeeman effect as well as the anomalous Zeeman effect are studied using a cadmium […]

Zeeman effect with electromagnet

Principle The “Zeeman effect” is the splitting up of the spectral lines of atoms within a magnetic field. The simplest is the splitting up of one spectral line into three components called the “normal Zeeman effect”. In this experiment the normal Zeeman effect as well as the anomalous Zeeman effect are studied using a cadmium […]

Planck’s “quantum of action” and photoelectric effect(line separation by interference filters)

PrincipleA photocell is illuminated with monochromatic light of different wavelengths from a filament lamp with interference filters. The maximum energy of the ejected electrons in the photo-cell depends only on the frequency of the incident light, and is independent of its intensity. The stopping voltage Uo at different light frequencies is determined by the U/I caracteristics of the […]

Diffraction at a slit and Heisenberg’s uncertainty principle

Principle The distribution of intensity in the Fraunhofer diffraction pattern of a slit is measured. The results are evaluated both from the wave pattern view point, by comparison with Kirchhoff’s diffraction formula, and from the quantum mechanics standpoint to confirm Heisenberg’s uncertainty principle. Benefits quantum mechanical versus wave theory viewpoints are discussed observing light transversing […]

Duane-Hunt displacement law and Planck’s “quantum of action”

Principle X-ray spectra are recorded as a function of the anode voltage. The short wavelength limit of the bremsspectrum is used to determine the agreement with the Duane-Hunt displacement law, and to determine Planck’s “quantum of action”. Tasks Record the intensity of the X-rays emitted by the copper anode at various anode voltages as a […]

Compton scattering of X-rays

PrincipleCompton scattering is to be achieved by directing an X-ray beam against a piece of plastic. The portions of the scattered X-rays at various angles is to be measured with a counter tube. Measurements are to be made with an absorber positioned in front of and behind the scatterer, so that the Compton wave length […]

Compton effect – energy-dispersive direct measurement

Principle Photons of the molybdenum Kα X-ray line are scattered at the quasi-free electrons of an acrylic glass cuboid. The energy of the scattered photons is determined in an angle-dependent manner with the aid of a swivelling semiconductor detector and a multi-channel analyser. Tasks Energy calibration of the multi-channel analyser with the aid of the two […]

Compton effect

PrincipleWhen photons are scattered on electrons, their momentum and energy gets changed. The energy of scattered gamma-radiation is measured as a function of the angle of scatter. The Compton wavelength is determined from the measured values. Tasks Calibrate the measuring set-up with the aid of a Cs-137 calibrating source (37 kBq) and a Na-22 source […]

Electron diffraction

Principle Fast electrons are diffracted from a polycrystalline layer of graphite: interference rings appear on a fluorescent screen. The interplanar spacing in graphite is determined from the diameter of the rings and the accelerating voltage. Tasks To measure the diameter of the two smallest diffraction rings at different anode voltages. To calculate the wavelength of […]

Electron spin resonance

Principle With electron spin resonance (ESR) spectroscopy compounds having unpaired electrons can be studied. The physical background of ESR is similar to that of nuclear magnetic resonance (NMR), but with this technique electron spins are excited instead of spins of atomic nuclei. The g-factor of a DPPH (Diphenylpikrylhydrazyl) specimen and the halfwidth of the absorption line […]

Magnetic Resonance Imaging (MRI) II

Principle The aim of these experiments is to show how the spin echo technique can be used to generate 2D MR images of a slice of a well-defined thickness, orientation, and size (Localized Spin Echo 2D). These parameters determine the so-called “field of view” (FOV) of the MR image. We will introduce a method that […]

Magnetic Resonance Imaging (MRI) I

Principle The basic principles of 2D MR imaging are demonstrated with two methods relying on two different gradient techniques. Experiments are executed with a MRT training device giving the opportunity to investigate some small probes in the sample chamber. Device control is done with the provided software. Investigations comprise the generation of a two-dimensional cross-section […]

Spatial encoding in Nuclear Magnetic Resonance

Principle It should be demonstrated how spatial encoding does work in the MR technology. Experiments are executed with a MRT training device giving the opportunity ton investigate some small probes in the sample chamber. Device control is done with the provided software. Investigations comprise the generation of a 1D spatial encoding procedure via an additional […]

Relaxation times in Nuclear Magnetic Resonance

PrincipleThe principles of relaxation processes using the MR technology are demonstrated. Experiments are executed with the MRT training device giving the opportunity to investigate some small probes in the sample chamber. Device control is done with the provided software. Investigations comprise the estimation of the relaxation time T1 which is a measure of time for reestablishing […]

Stern-Gerlach experiment

Principle A beam of potassium atoms generated in a hot furnace travels along a specific path in a magnetic two-wire field. Because of the magnetic moment of the potassium atoms, the non-homogeneity of the field applies a force at right angles to the direction of their motion. The potassium atoms are thereby deflected from their […]

Franck-Hertz experiment with a Ne-tube

Principle Electrons are accelerated in a tube filled with neon vapour. The excitation energy of neon is determined from the distance between the equidistant minima of the electron current in a variable opposing electric field. Tasks To record the counter current strength I in a Franck-Hertz tube as a function of the anode voltage U. To determine the […]

Franck-Hertz experiment with a Hg-tube

Principle Electrons are accelerated in a tube filled with mercury vapour. The excitation energy of mercury is determined from the distance between the equidistant minima of the electron current in a variable opposing electric field. Benefits Experience the essence of the Nobel Price: Franck, Hertz (1925) Classical Version with Mercury (Hg) One operating unit for […]

Specific charge of the electron – e/m

PrincipleElectrons are accelerated in an electric field and enter a magnetic field at right angles to the direction of motion. The specific charge of the electron is determined from the accelerating voltage, the magnetic field strength and the radius of the electron orbit. Tasks Determination of the specific charge of the electron (e/m0) from the […]

Elementary charge and Millikan experiment

Principle Charged oil droplets subjected to an electric field and to gravity between the plates of a capacitor are accelerated by application of a voltage. The elementary charge is determined from the velocities in the direction of gravity and in the opposite direction. Tasks Measurement of the rise and fall times of oil droplets with […]

Quantum eraser with the Mach-Zehnder interferometer

Principle A Mach-Zehnder-interferometer is illuminated with a laser beam. Circular interference fringes appear on the screens behind the interferometer. If polarisation filters with opposite polarisation planes are placed in the two interferometer paths the interference patterns disappear. Placing another polariser before one of the screens causes the pattern to reappear. Electromagnetic radiation can be described […]

Ferromagnetism, paramagnetism and diamagnetism

PrincipleThe aim of this experiment is to study the behaviour of nickel, tungsten, and bismuth rods in a strong, inhomogeneous magnetic field. This field is formed, for example, between cone-shaped pole pieces that sit on a permanent magnet. The rods are suspended horizontally on a long and very thin silk thread so that they can […]

RLC measuring bridge

PrincipleOhmic resistances, inductances and capacitances are determined in a Wheatstone bridge circuit operated on AC. Balancing is done aurally through headphones, using the high sensitivity of the human ear. Benefits Quickly obtain experiment results using the Wheatstone bridge Easy to tune by aural measurement relying on the sensitivity of the human ear Save time while […]

RC filters

PrincipleResistor-Capacitor (RC) circuits serve as filters for frequencies. The frequency response of the most commonly used RC filters is recorded by point-by-point measurements as well as the frequency sweep method, and displayed on the oscilloscope. The results are plotted and verified using the measure analysis software. Benefits Investigate several types of frequency filters High-resistance inputs […]

Magnetic induction

Principle A magnetic field of variable frequency and varying strength is produced in a long coil. The voltages induced across thin coils which are pushed into the long coil are determined as a function of frequency, number of turns, diameter and field strength. Benefits Huge field coil for homogenous magnetic field On-the-fly switching of the […]

Determination of the earth’s magnetic field

Principle A constant magnetic field, its magnitude and direction known, is superimposed on the unknown earth magnetic field. The earth-magnetic field can then be calculated from the magnitude and direction of the resulting flux density. Benefits Particularly homogeneous magnetic field and high flux density due to large Helmholtz coil diameter Setup with precalibrated teslameter does […]

Current balance / force acting on a current-carrying conductor with an amperemeter

Principle The force acting on a current-carrying conductor loop in a uniform magnetic field (Lorentz force) is measured with a balance. Conductor loops of various sizes are suspended in turn from the balance, and the Lorentz force is determined as a function of the current and magnetic induction. The uniform magnetic field is generated by […]

Coulomb’s law/ image charge

PrincipleA small electrically charged ball is positioned at a certain distance in front of a metal plate lying at earth potential. The surface charge on the plate due to electrostatic induction together with the charged ball forms an electric field analogous to that which exists between two oppositely charged point charges. The electrostatic force acting […]

Diffraction and Interference of Microwaves

Principle If a double-slit is positioned in the divergent microwave beam, a characteristic intensity profile results behind this double-slit. The periodicity of the intensity profile can be used to determine the wavelength of the microwaves that are used. Benefits Convenient all-in-one set includes control unit, transmitter and receiver as horn antennae, microwave probe, microwave benches, […]

Temperature dependence of different resistors and diodes with a multimeter

Principle The temperature dependence of an electrical parameter (e.g. resistance, conducting-state voltage, blocking voltage) of different components is determined. To do this, the immersion probe set is immersed in a water bath and the resistance is measured at regular temperature intervals. Benefits Onesetup to measure both electrical components and semiconducting diodes, as well as the […]

Characteristic curve and efficiency of a PEM fuel cell and a PEM electrolyser

Principle In a PEM electrolyser, the electrolyte consists of a proton-conducting membrane and water (PEM = Proton-Exchange-Membrane). When an electric voltage is applied, hydrogen and oxygen are formed. The PEM fuel cell generates electrical energy from hydrogen and oxygen. The electrical properties of the electrolyser and the fuel cell are investigated by recording a current-voltage […]

Conservation of Energy in Reflection and Transmission of Microwaves

Principle When electromagnetic waves encounter an obstacle, they are proportionately reflected, transmitted and absorbed. In this experiment, it is proved that the sum of the proportions is conserved. Benefits Convenient all-in-one set includes control unit, transmitter and receiver as horn antennae, microwave probe, microwave benches, grating, slit plates, prism, and reflection/absorption plates With the same […]

Standing Waves in the Range of Microwaves

Principle When electromagnetic waves are bounced back and forth between two reflectors, a standing wave is formed. From the wavelength of the standing wave, the frequency of the waves can be determined. Benefits Convenient all-in-one set includes control unit, transmitter and receiver as horn antennae, microwave probe, microwave benches, grating, slit plates, prism, and reflection/absorption […]

Propagation of Microwaves (Inverse Square Law)

Principle The intensity of a source of radiation, e.g. a microwave transmitter, at any given location depends on the distance of this location from the (approximately punctiform) source. Actually, due to its antenna geometry, a microwave transmitter can only be regarded as a punctiform source of radiation at long distances, which is why it is […]

Reflection, Transmission and Refraction of Microwaves

Principle When electromagnetic waves encounter an obstacle, phenomena like reflection, transmission and refraction occur. In the present experiment these phenomena are verified and described by means of microwaves. Benefits Convenient all-in-one set includes control unit, transmitter and receiver as horn antennae, microwave probe, microwave benches, grating, slit plates, prism, and reflection/absorption plates With the same […]

Polarization of Microwaves

Principle Electromagnetic waves impact on a grating whose permeability depends on the rotation plane of the wave. Benefits Convenient all-in-one set includes control unit, transmitter and receiver as horn antennae, microwave probe, microwave benches, grating, slit plates, prism, and reflection/absorption plates With the same set, all aspects of microwave physics can be studied quantitatively: polariziation, reflection, […]

Resistance, phase shift and power in AC circuits with digital function generator

PrincipleSeries circuits containing self-inductances or capacitances and ohmic resistances are investigated as a function of frequency. Measuring the electrical magnitudes with a work or power measurement instrument, real power or apparent power can be displayed directly. Benefits Quick set-up Investigate the influence of electrical components in an AC circuit. Directly measure the real or apparent […]

Rectifier circuits

PrincipleThe ripple of the output voltage of various rectifier circuits is measured as a function of the load current strength and the charging capacitance. The characteristics of a voltage stabilizer and of a multiplier are investigated. Benefits Get to know several types of rectifier circuits Suitable for vocational classes Tasks Using the half-wave rectifier: To […]

RLC circuit with Cobra4 Xpert-Link

Principle In an RLC circuit, energy is exchanged periodically between a capacitor and a coil. When the electric field of the capacitor decreases by discharge over the coil, a magnetic field is established in the coil. As soon as the capacitor is completely depleted, the current flow through the coil vanishes. The magnetic field decreases […]

Capacitor in the AC circuit with Cobra4 Xpert-Link

Principle A capacitor is connected in a circuit with a variable-frequency voltage source. The impedance and phase displacement are determined as a function of frequency and of capacitance. Parallel and series impedances are measured. Benefits Intuitive, touch-optimized software that controls all devices simultaneously Simplified implementation: all pre-settings already prepared Easy frequency setting thanks to digital […]

Inductance of solenoids

PrincipleA square wave voltage of low frequency is applied to oscillatory circuits comprising coils and capacitors to produce free, damped oscillations. The values of inductance are calculated from the natural frequencies measured, the capacitance being known. Benefits Quick, easy, and neat set-up On-the-fly switching of the numerous induction coils for quick and easy experimenting Easy […]

Induced voltage pulse and Faraday’s law of induction with Cobra4 Xpert-Link

Principle A permanent magnet drops through a coil with different velocities. The change in the magnetic flux generates an induced voltage pulse. It is shown that the total induced voltage during the entire fall is constant and therefore independent of the velocity. In respect to the magnet polarity, the induced voltage changes from plus to minus or vice versa. Benefits […]

Transformer

Principle An alternating voltage is applied to one of two coils (primary coil) which are located on a common iron core. The voltage induced in the second coil (secondary coil) and the current flowing in it are investigated as functions of the number of turns in the coils and of the current flowing in the […]

Elementary charge and Millikan experiment

Principle Charged oil droplets subjected to an electric field and to gravity between the plates of a capacitor are accelerated by application of a voltage. The elementary charge is determined from the velocities in the direction of gravity and in the opposite direction. Tasks Measurement of the rise and fall times of oil droplets with […]

Magnetostriction with the Michelson interferometer

PrincipleWith the aid of two mirrors in a Michelson arrangement, light is brought to interference. Due to the magnetostrictive effect, one of the mirrors is shifted by variation in the magnetic field applied to a sample and the change in the interference pattern is observed. Benefits See that magnetic fields can change the geometry of […]

Ferromagnetic hysteresis with Cobra4

Principle A magnetic field is generated in a ring-shaped iron core by a continuous adjustable direct current applied to two coils. The field strength Η and the flux density B are measured and the hysteresis recorded. The remanence and the coercive field strength of two different iron cores can be compared. Benefits Simple experimental setup and intuitive handling of […]

Magnetic field outside a straight conductor

Principle A current which flows through one or two neighbouring straight conductors produces a magnetic field around them. The dependences of these magnetic fields on the distance from the conductor and on the current are determined. Benefits Four different current conductors allow the observation of the magnetic field in different configurations Experimental setup allows the […]

Magnetic field inside a conductor with digital function generator

PrincipleA current is passed through an electrolyte producing a magnetic field. This magnetic field inside the conductor is measured as function of position and current by determining the induction voltage. Benefits Measure the magnetic field inside of liquid electrolytes Large unique hollow cylinder with conductive wire mesh prevents the influence of disturbing fields Easy frequency […]

Magnetic moment in the magnetic field

Principle A conductor loop carrying a current in an uniform magnetic field experiences a torque. This is determined as a function of the radius, of the number of turns and the current in the conductor loop and of the strength of the external field. Benefits Particularly homogeneous magnetic field and high flux density due to […]

Magnetic field of paired coils in a Helmholtz arrangement with a teslameter

Principle The spatial distribution of the field strength between a pair of coils in the Helmholtz arrangement is measured. The spacing at which a uniform magnetic field is produced is investigated and the superposition of the two individual fields to form the combined field of the pair of coils is demonstrated. Benefits Particularly homogeneous magnetic […]

Magnetic field of single coils / Biot-Savart’s law with a teslameter

Principle The magnetic field along the axis of wire loops and coils of different dimensions is measured with a teslameter (Hall probe). The relationship between the maximum field strength and the dimensions is investigated and a comparison is made between the measured and the theoretical effects of position. Benefits Simple setup which allows an easy […]

Semiconductor thermogenerator – Seebeck effect

Principle In a semi-conductor thermogenerator, the no-load voltage and the short-circuit current are measured as a function of the temperature difference. The internal resistance, the Seebeck coefficient and the efficiency are determined. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment […]

Characteristic curves of semiconductors with Cobra4 Xpert-Link

Principle Determine the current strength flowing through a semi-conducting diode. Determine the collector current with the collector voltage for various values of the base current intensity. Benefits Fast and easy experimenting Get to know the behaviour of several types of semiconductors Detailed experiment guide with extensive explanations and step-by-step instructions Measure voltage and current simultaneously […]

Characteristic curves of semiconductors with Cobra4

PrincipleThe current-voltage characteristic of a semiconducting diode is measured. The collector current in dependency on the emitter-collector voltage is measured for different values of base current strength through a NPN transistor. Benefits Fast and easy experimenting Get to know the behaviour of several types of semiconductors Simplified implementation: all pre-settings already prepared Data logging reveals instantaneous […]

Characteristic curves of a solar cell

Principle The current-voltage characteristics of a solar cell are measured at different light intensities, the distance between the light source and the solar cell being varied. The dependence of no-load voltage and short-circuit current on temperature is determined. Benefits Set-up allows quantitative measurement which also takes light intensity into account Set-up allows to avoid but […]

Kirchhoff’s laws

Principle Kirchhoff’s laws are verified by measuring current, voltage and resistance in series and parallel circuits. In addition, the Wheatstone bridge circuit is used to determine unknown resistances more precisely. Benefits Setup to measure both Kirchhoff’s laws and to determine unknown resistances Components can also be used for other basic and advanced electricity experiments Tasks […]

Wheatstone bridge

Principle The Wheatstone bridge circuit is used to determine unknown resistances. The total resistance of resistors connected in parallel and in series is measured. Benefits Highly precise and reproducible measurements possible Many different measurement variations possible Also suitable for measurement of low resistances Tasks Determination of unknown resistances. Determination of the total resistance of resistors […]

4 Point Method / Measurement of low resistances / Ohm’s Law

Principle The resistances of various DC conductors are determined by recording the current / voltage characteristic. The resistivity of metal rods and the contact resistance of connecting cords are calculated. Benefits Measurement at two different metals possible Conductivity rods can be used both for electrical and thermal conductivity experiments Measurement amplifier can be used for […]

Dielectric constant of different materials

PrincipleThe electric constant is determined by measuring the charge of a plate capacitor to which a voltage is applied. The dielectric constant is determined in the same way, with plastic or glass filling the space between the plates. Benefits Supplies non-hazardous high voltage Easy experimental set-up due to clear and compact design Clever investment: The […]

Capacitance of metal spheres and of a spherical capacitor

PrincipleMetal spheres with different radii and a spherical capacitor are charged by means of a variable voltage. The induced charges are determined with a measuring amplifier. The corresponding capacitances are deduced from voltage and charge values. Benefits Supplies non-hazardous high voltage Several conductive spheres included Clever investment: The included universal measuring amplifier can also be […]

Charging curve of a capacitor and switch-on behaviour of an inductance with Cobra4 Xpert-Link

Principle A capacitor is charged by way of a resistor. The current is measured as a function of time and the effects of capacitance, resistance and the voltage applied are determined. Benefits Simple and very clear set-up: only few components required Cost savings: Xpert-Link provides all subsidiary functions (power supply, switch, trigger) Extra experiment included: […]

Charging curve of a capacitor / charging and discharging of a capacitor

Principle A capacitor is charged by way of a resistor. The current is measured as a function of time and the effects of capacitance, resistance and the voltage applied are determined. Benefits Simple and very clear set-up: only few components required Further experiments in electricity and electronics can be performed with the equipment Tasks To […]

Electron spin resonance

Principle With electron spin resonance (ESR) spectroscopy compounds having unpaired electrons can be studied. The physical background of ESR is similar to that of nuclear magnetic resonance (NMR), but with this technique electron spins are excited instead of spins of atomic nuclei. The g-factor of a DPPH (Diphenylpikrylhydrazyl) specimen and the halfwidth of the absorption line […]

Coulomb potential and Coulomb field of metal spheres

Principle Conducting spheres with different diameters are charged electrically. The static potentials and the accompanying electric field intensities are determined by means of an electric field meter with a potential measuring probe, as a function of position and voltage. Benefits Supplies non-hazardous high voltage Loss-less measurement of electric field strength High-sensitive electric field meter also […]

Electric fields and potentials in the plate capacitor

PrincipleA uniform electric field E is produced between the charged plates of a plate capacitor. The strength of the field is determined with the electric field strength meter, as a function of the plate spacing d and the voltage U. The potential ø within the field is measured with a potential measuring probe. Benefits Loss-less measurement of electric field […]

Inductance of solenoids with Cobra4 Xpert-Link

Principle A square wave voltage of low frequency is applied to oscillatory circuits comprising coils and capacitors to produce free, damped oscillations. The values of inductance are calculated from the natural frequencies measured, the capacitance being known. Benefits On-the-fly switching of the numerous induction coils for quick and easy experimenting Intuitive, touch-optimized software that controls […]

Newton’s rings with interference filters

Principle In a Newton’s rings apparatus, monochromatic light interferes in the thin film of air between the slightly convex lens and a plane glass plate. The wavelengths are determined from the radii of the interference rings. Benefits the color of soap bubbles is based on it: interference in thin films use interference optics to determine […]

Faraday’s laws

Principle   Faraday’s first law states that the mass of a material separated by electrolysis is proportional to the quantity of electricity which flowed through the solution. The second law states that the electrochemical equivalents are proportional to their equivalent masses (molar mass divided by valency). The experimental setup depicted here can be used to […]

Polarimetry

Principle The rotation of the plane of polarisation through a sugar solution measured with a half-shade  polarimeter and the reaction rate constant for the inversion of cane sugar determined. Benefits even transparent fluids can change the properties of light passing them find out how fast one type of sugar changes into another one use optical […]

Michelson interferometer

Principle In the Michelson arrangement interference will occur by the use of 2 mirrors. The wavelength is determined by displacing one mirror using the micrometerscrew. Benefits discover the essence of the Physics Nobel Prize of 1907 lead to experimental findings that only special relativity theory could explain pre setup of the critical components makes for […]

Index of refraction, dipersion, and resolving power of a prism spectroscope

Principle The spectrometer-goniometer is used to determine the angle of deflection that light undergoes when passing a prism. The refractive index of a prism at the specific wavelength of a known spectral line can be determined by observation of the angle of least deflection of light of that spectral line effected by that prism, given […]

Faraday effect

Principle The angle of rotation of the polarisation- plane of plane polarised light through a flint glass rod is found to be a linear function of the product of the mean flux-densitiy and the length of the optical medium. The factor of proportionally, called Verdet’s constant, is investigated as a function of the wavelength and […]

Malus’ law

Principle Linear polarised light passes through a polarisation filter. Transmitted light intensity is determined as a function of the angular position of the polarisation filter. Benefits the principle that Polaroid glasses work on introductory yet quantitative experiment to polarization straightforward simple setup Tasks The plane of polarisation of a linear polarised laser beam is to […]

Polarisation through quarter-wave plates

Principle Monochromatic light falls on a mica plate perpendicular to its optic axis. At the appropriate plate thickness (lambda/4, or quarter-wave plate) there is a 90° phase shift between the ordinary and the extraordinary ray when the light emerges from the crystal. The polarisation of the emergent light is investigated at different angles between the […]

X-ray investigation of crystal structures / Laue method

Principle Laue diagrams are produced when monocrystals are irradiated with polychromatic X-rays. This method is primarily used for the determination of crystal symmetries and the orientation of crystals. When a LiF monocrystal is irradiated with polychromatic X-rays, a characteristic diffraction pattern results. This pattern is photographed and then evaluated. Tasks The Laue diffraction of an […]

Examination of the structure of NaCl monocrystals with different orientations

Principle The spectra of the X-rays that are reflected with various different orientations by NaCl monocrystals are analysed. The associated interplanar spacings are determined based on the Bragg angles of the characteristic lines. Tasks Determine the intensity of the X-rays that are reflected by the NaCl monocrystals with the orientations [100], [110] and [111] as […]

Magnetostriction with the Michelson interferometer

PrincipleWith the aid of two mirrors in a Michelson arrangement, light is brought to interference. Due to the magnetostrictive effect, one of the mirrors is shifted by variation in the magnetic field applied to a sample and the change in the interference pattern is observed. Benefits See that magnetic fields can change the geometry of […]

Fabry-Perot interferometer – optical resonator modes

Principle Two mirrors are assembled to form a Fabry-Perot interferometer. Using them, the multibeam interference ofa laser’s light beam is investigated.On moving one of the mirrors, thechange in the intensity distributionof the interfeence pattern is studied. This is a qualitative experiment,to study the shape of different lasermodes and compare it with some photosgiven in this […]

Quantum eraser with the Mach-Zehnder interferometer

Principle A Mach-Zehnder-interferometer is illuminated with a laser beam. Circular interference fringes appear on the screens behind the interferometer. If polarisation filters with opposite polarisation planes are placed in the two interferometer paths the interference patterns disappear. Placing another polariser before one of the screens causes the pattern to reappear. Electromagnetic radiation can be described […]

Diffraction intensity at a slit and at a wire – Babinet’s theorem

Principle An aperture consisting of a single slit and a complementary strip (wire) is illuminated with a laser beam. The corresponding diffraction patterns are measured according to position and intensity with a photocell which can be shifted. Benefits surprisingly a slit and a wire show basically the same diffraction pattern measurements prove a theorem that […]

Diffraction intensity due to multiple slits and grids

Principle Multiple slits which all have the same width and the same distance among each other, as well as transmission grids with different grid constants, are submitted to laser light. The corresponding diffraction patterns are measured according to their position and intensity, by means of a photo diode which can be shifted. Benefits understand what […]

Diffraction of light at a slit and an edge

Principle Monochromatic light is incident on a slit or an edge. The intensity distribution of the diffraction pattern is determined. Benefits learn that the transition region from light to shadow is not a sharp line, but a diffraction pattern you can make use of diffraction patterns to determine properties of the objects causing them simple […]

Michelson interferometer – High Resolution

Principle With the aid of two mirrors in a Michelson arrangement, light is brought to interference. While moving one of the mirrors, the alterationin the interference pattern is observed and the wave length of the laser light determined. Benefits Learn about the measurement principle with which gravitational waves can be observed Assemble your own interferometer using invidual optical components […]

Refraction index of air and CO2 with the Michelson interferometer

Principle A measurement cuvette set in the beam path of a Michelson interferometer can be evacuated or filled with CO2. The refraction indexes of air or CO2 are determined through the assessed modification of the interference pattern. Benefits see that even two transparent gases can have different optical properties a Michelson interferometer is used to measure subtle differences […]

Coherence and width of spectral lines with the Michelson interferometer

Principle The wavelengths and the corresponding lengths of coherence of the green spectral lines of an extreme high pressure Hg vapour lamp are determined by means of a Michelson interferometer. Different double slit combinations are illuminated to verify the coherence conditions of non punctual light sources. An illuminated auxiliary adjustable slit acts as a non […]

Structure of a Fresnel zone plate

Principle A zone plate is illuminated with parallel laser light. The focal points of several orders of the zone plate are projected on a ground glass screen. Benefits find out that optical lenses can be completely different from what you are used to interference is used to produce effects commonly achieved with diffraction the use […]

Laws of lenses and optical instruments

PrincipleThe focal lengths of unknown lenses are determined by measuring the distances of image and object and by Bessel’s method. Simple optical instruments are then constructed with these lenses. Tasks To determine the focal length of two unknown convex lenses by measuring the distances of image and object. To determine the focal length of a […]

Fibre optics

Principle The beam of a laser diode is treated in a way that it can be coupled into a monomode fibre. The problems related to coupling the beam into the fibre are evaluated and verified. In consequence a low frequency signal is transmitted through the fibre. The numerical aperture of the fibre is recorded. The […]

Fresnel’s law – theory of reflection

Principle Plane-polarized light is reflected at a glass surface. Both the rotation of the plane of polarization and the intensity of the reflected light are to be determined and compared with Fresnel’s formulare for reflection. Benefits see that reflection at a glass surface changes some properties of light find out that at special angles, light […]

Interference of light

Principle By dividing up the wave-front of a beam of light at the Fresnel mirror and the Fresnel biprism, interference is produced. The wavelength is determined from the interference patterns. Benefits observe that light plus light can result in darkness understand how to make use of the interference effect a laser as lightsource allows clear […]

Dispersion and resolving power of a grating spectroscope

Principle The diffracted light from a periodic line grating is observed with a goniometer. The diffraction angles of spectral lines in different orders of diffraction are measured for the spectral lines from a Hg spectral lamp. By using gratings with different grating constants the angular spectral dispersion in dependence on grating constant is determined. The […]

Lambert’s law of radiation on optical base plate

Principle Visible light impinges on a diffusely reflecting surface. The luminance of this surface is determined as a function of the angle of observation. Benefits study the light intensity that a sheet of paper is diffusely reflecting learn about the different physical units associated with light very versatile optical base plate Tasks The luminous flux […]

Photometric law of distance with Cobra4 – inverse square law

Principle The luminous intensity emitted by a punctual source is determined as a function of distance. Benefits find out how exactly it becomes darker with increasing distance from a lightsource get results fast and reproducible with a data-logging system analize results easily and compare them to theory using a computer Tasks The luminous intensity emitted […]

Measuring the velocity of light

Principle The intensity of the light is modulated and the phase relationship of the transmitter and receiver signal compared. The velocity of light is calculated from the relationship between the changes in the phase and the light path. Benefits determine yourself what the “speed of light” actually is find out how the velocity of light […]

Solar ray collector

Principle The solar ray collector is illuminated with a halogen lamp of known light intensity. The heat energy absorbed by the collector can be calculated from the volume flow and the difference in the water temperatures at the inlet and outlet of the absorber, if the inlet temperature stays almost constant by releasing energy to […]

Thermal expansion in solids and liquids

Principle The volume expansion of liquids and the linear expansion of various materials is determined as a function of temperature. Benefits With detailed experiment guide Two experiments in one Tasks To determine the volume expansion of ethyl acetate (C4H8O2), methylated spirit, olive oil, glycerol and water as a function of temperature, using the pycnometer. To determine […]

Adiabatic coefficient of gases – Flammersfeld oscillator

Principle A mass oscillates on a volume of gas in a precision glass tube. The oscillationis maintained by leading escaping gas back into the system. The adiabatic coefficient of various gases is determined from the periodic time of the oscillation. Benefits Suitable for many different gases Compact, easily transportable setup Tasks Determine the adiabatic coefficient […]

Thermal equation of state and critical point

Principle A substance which is gaseous under normal conditions is enclosed in a variable volume and the variation of pressure with the volume is recorded at different temperatures. The critical point is determined graphically from a plot of the isotherms. Benefits Visualization of the critical point Tasks Measure a number of p-V isotherms of ethane. […]

Heat capacity of gases with Cobra4

Principle Heat is added to a gas in a glass vessel by an electric heater which is switched on briefly. The temperature increase results in a pressure increase, which is measured with a manometer. Under isobaric conditions a temperature increase results in a volume dilatation, which can be read from a gas syringe. The molar […]

Vapour pressure of water below 100°C – molar heat of vaporisation

Principle The vapour pressure of water in the range of 40 °C to 85 °C is investigated. It is shown that the Clausius-Clapeyron equation describes the relation between temperature and pressure in an adequate manner. An average value for the heat of vaporisation of water is determined. Benefits Compact, easily transportable setup For both demonstration […]

Emittance of hot bodies (Leslie cube)

Principle Thermal radiation can be measured at all surfaces as long as their temperature differs from that of the surrounding. Therefore it applies that the hotter an object is, the more radiation it emits. Also the surface colour influences the behaviour: dark surfaces emit more thermal radiation than light ones. An example for application of […]

Electric compression heat pump

Principle Pressures and temperatures in the circulation of the heat electrical compression heat pump are measured as a function of time when it is operated as a water-water heat pump. The energy taken up and released is calculated from the heating and cooling of the two water baths. When it is operated as an air-water […]

Semiconductor thermogenerator – Seebeck effect

Principle In a semi-conductor thermogenerator, the no-load voltage and the short-circuit current are measured as a function of the temperature difference. The internal resistance, the Seebeck coefficient and the efficiency are determined. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment […]

Thermal and electrical conductivity of metals

Principle The thermal conductivity of copper and aluminium is determined in a constant temperature gradient from the calorimetrically measured heat flow. The electrical conductivity of copper and aluminium is determined and the Wiedmann-Franz law is tested. Benefits Measurement of electrical and thermal conductivity in one set-up Compact, easily transportable setup Tasks Determine the heat capacity […]

Peltier heat pump

Principle The (cooling capacity) heating capacity and efficiency rating of a Peltier heat pump are determined under different operating conditions. Benefits Open design allows to fully understand function and applications Individual instruments for distinct functions (no “black box”) Key products of the experiment setup can also be used for investigating the Seebeck effect Tasks To determine the […]

Stefan-Boltzmann’s law of radiation with an amplifier

Principle According of Stefan-Boltzmann’s law, the energy emitted by a black body per unit area and unit time is proportional to the power “four” of the absolute temperature of the body. Stefan-Boltzmann’s law is also valid for a so-called “grey” body whose surface shows a wavelength independent absorption-coefficient of less than one. In the experiment, […]

Cooling by evacuation

Principle When the air pressure above a watersurface is reduced, the water begins to boil at a certain temperature. The temperature of the water is hereby reduced and further evacuation can finally bring it to 0 °C and even lower. Benefits Data logging via tablet possible. For both demonstration and student experiments Tasks Determine the […]

Mechanical equivalent of heat

Principle In this experiment, a metal test body is rotated and heated by the friction due to a tensed band of synthetic material.The mechanical equivalent of heat for problem 1 is determined from the defined mechanical work and from the thermal energy increase deduced from the increase of temperature. Assuming the equivalence of mechanical work […]

Heat capacity of metals

Principle Heated specimens are placed in a calorimeter filled with water at low temperature. The heat capacity of the specimen is determined from the rise in the temperature of the water. Benefits Compact, easily transportable setup For both demonstration and student experiments Tasks To determine the heat capacity of the calorimeter by filling it with […]

Heat capacity of metals with Cobra4

Principle Heated specimens are placed in a calorimeter filled with water at low temperature. The heat capacity of the specimen is determined from the rise in the temperature of the water. Benefits Flexible experimenting thanks to wireless data transmission Data acquisition with tablets possible Simplified implementation: all pre-settings already prepared Tasks To determine the specific […]

Joule-Thomson effect

Principle A stream of gas is fed to a throttling point, where the gas (CO2 or N2) undergoes adiabatic expansion. The differences in temperature established between the two sides of the throttle point are measured at various pressures and the Joule-Thomson coefficients of the gases in question are calculated. Benefits For both demonstration and student experiments With […]

Heat capacity of gases

Principle Heat is added to a gas in a glass vessel by an electric heater which is switched on briefly. The temperature increase results in a pressure increase, which is measured with a manometer. Under isobaric conditions a temperature increase results in a volume dilatation, which can be read from a gas syringe. The molar […]

Vapour pressure of water at high temperature

Principle The high-pressure steam apparatus makes it possible to measure steam pressure in a temperature range of 100-250 °C. This allows for investigations to be performed on real gases and vapours. Typical equilibrium states between gas and liquid phases can be set up. For this purpose, water is heated in a closed pressure chamber at […]

Maxwellian velocity distribution

Principle By means of the model apparatus for kinetic theory of gases the motion of gas molecules is simulated and the velocities determined by registration of the throw distance of the glass balls. This velocity distribution is compared to the theoretical Maxwell- Boltzmann equation. Benefits For both demonstration and student experiments Unique experiment to quantitatively […]

Equation of state for ideal gases with Cobra4 (gas laws: Gay-Lussac, Amontons, Boyle)

Principle The state of a gas is determined by temperature, pressure and amount of substance. For the limiting case of ideal gases, these state variables are linked via the general equation of state. For a change of state under isochoric conditions this equation becomes Amontons’ law. In this experiment it is investigated whether Amontons’ law […]

Velocity of sound using Kundt’s tube and digital function generator

Principle Cork dust in a glass tube is set into tiniest motion by a sound wave. If the frequency of the sound wave matches the natural frequency of the volume in the glass tube, a standing wave will form. The cork dust then assembles in visible patterns that show the nodes of pressure and motion […]

Vibration of strings

Principle A tensioned metal string is made to vibrate. The vibrations of the string are optically scanned, the vibration process observed on the oscilloscope and the dependence of the frequency on the string tension and string length and the density of the material are investigated. Benefits Investigation of the dependency of the vibration frequencies of […]

Phase velocity of rope waves

Principle A quadrangular rubber rope is inserted through the demonstration motor and a linear polarised fixed wave is generated. With the help of a stroboscope, the frequency and the wave length are determined. Then the phase velocity of ropewaves with a fixed tensile stress is ascertained. Subsequently, the mathematical relationship between the phase velocity of […]

Velocity of ultrasound in solid state material

Principle The velocity of sound in acrylics shall be determined by time of flight reflection technique with an ultrasonic echoscope. The measurements are done by reflection method, on three cylinders of different length. Two measurement series are carried out with ultrasonic probes of different frequencies. Benefits Introductory experiment for echoscopy applications Experiment can be easily […]

Ultrasonic echography (B-Scan)

Principle The fundamental principles concerning the generation of ultrasonic B-scan images (brightness representation of the reflection amplitudes) are demonstrated with the aid of a simple test ob-ject. The experiment is executed with an ultrasonic echoscope in the pulse-echo-mode and the object is scanned manually. Then, the image quality and the most important image defects will […]

Ultrasonic echography (A-Scan)

Principle An ultrasonic wave transmitted in a sample will be reflected at discontinuities (defects, cracks). From the relationship between the time of flight of the reflected wave and the sound velocity, the distance between ultrasonic transducer and defects (reflector) can be calculated. Position and size of these defects can be determined by measuring in different […]

Resonance frequencies of Helmholtz resonators with Cobra4 Xpert-Link

Principle Acoustic cavity resonators possess a characteristic frequency which is determined by their geometrical form. In this case the resonator is excited to vibrations in its resonance frequency by background noise. Benefits Measure the resonance frequencies without additional excitation by using only the ambient noise Immediate observation of both, the sound wave signal and the […]

Acoustic Doppler effect with universal counter

Principle If an emitter of sound or a detector is set into motion relative to the medium of propagation, the frequency of the waves that are emitted or detected is shifted due to the Doppler effect. Benefits Easy frequency setting thanks to digital function generator Intuitive measuring instrument Results well reproducible because of the motor-driven […]

Velocity of sound in air with Universal Counter

Principle The velocity of sound in air is determined by measurement of sound travel times across known distances. Benefits Perfect as demonstration and student experiment Easy setup and fast procedure Easy entry into the topic of error calculation possible Tasks Determine the sound velocity in air for different distances between sound source and microphone. What […]

Measurement of the speed of sound in air with Cobra4

PrincipleThe velocity of sound in air is determined by measurements of sound travel times. Benefits Simple set-up and procedure Easy entry into the topic of error calculation possible Simplified implementation: all pre-settings already prepared Tasks Determine the speed of sound in air. What you can learn about Propagation of sound waves Velocity of sound Sound […]

Interference and diffraction of water waves with the Ripple Tank

Principle A set of circular water waves is generated simultaneously and the resulting interference is observed. By increasing the number of interfering circular waves, Huygens’ Principle can be verified. With the aid of plane water waves, diffraction phenomena of waves at different obstacles (slit, edge, double-slit etc.) are investigated. In a further experiment, the principle of […]

Propagation of a periodically excited continuous transverse wave

PrincipleThe periodicity of connected stationary oscillators is demonstrated on the example of a continuous, harmonic transverse wave generated by a wave machine. The number of oscillations carried out by different oscillators within a certain time is determined and the velocity of propagation is measured. A relation between frequency, wavelength and phase velocity is established. The […]

Chladni figures

PrincipleSquare and round metal plates are brought to vibrate through acoustic stimulations by a loudspeaker. When the driving frequency corresponds to a given Eigen-frequency (natural vibration mode) of the plate, the nodal lines are made visible with sand. The sand is expelled from the vibrating regions of the plate and gathers in the lines because […]

Torsional vibrations and torsion modulus

Principle Bars of various materials will be exciting into torsional vibration. The relationship between the vibration period and the geometrical dimensions of the bars will be derived and the specific shear modulus for the material determined. Benefits The use of eight different rods out of different material and with several diameters increase the understanding of […]

Forced oscillations – Pohl’s pendulum with measure Dynamics

Principle If an oscillating system is allowed to oscillate freely, we can observe that the decrement of successive maximum amplitudes strongly depends on the damping value. If the oscillating system is caused to oscillate by an external torsional oscillation, we can observe that the amplitude in a stationary state is a function of the frequency […]

Forced oscillations – Pohl’s pendulum

Principle If an oscillating system is allowed to swing freely it is observed that the decrease of successive maximum amplitudes is highly dependent on the damping. If the oscillating system is stimulated to swing by an external periodic torque, we observe that in the steady state the amplitude is a function of the frequency and […]

Harmonic oscillations of spiral springs – linked in parallel and in series with Cobra4

Principle The spring constant D is determined for different experimental set-ups from the oscillation period and the suspended mass. Tasks Determination of the spring constant D for different springs. Determination of the spring constant for springs linked in parallel. Determination of the spring constant for springs linked in series. Benefits Large and sturdy set-up suitable for demonstration and lab […]

Coupled pendula with measure Dynamics

Principle Two identical gravity pendula with a particular characteristic frequency are coupled via a “soft” spiral spring. The amplitudes of both pendula are recorded as a function of time. The coupling factors are determined by way of different methods. Then, the local points of the oscillation are integrated into the video. Benefits Large and sturdy […]

Coupled pendula with Cobra4 (advanced version)

Principle Two equal gravity pendula with a particular characteristic frequency are coupled by a “soft” spiral spring. The amplitudes of both pendula are recorded as a function of time for various vibrational modes and different coupling factors. The coupling factors are determined by different methods. Benefits Large and sturdy set-up suitable for demonstration and lab […]

Variable g pendulum

Principle Investigate the oscillation behaviour of a pendulum (rod pendulum) by varying the magnitude of the components of the acceleration of gravity which are decisive for the oscillation period. The pendulum that is to be used is constructed in such a manner that its oscillation plane can be progressively rotated from a vertical orientation to […]

Reversible pendulum

Principle By means of a reversible pendulum, terrestrial gravitational acceleration g may be determined from the period of oscillation of a physical pendulum, knowing neither the mass nor the moment of inertia of the latter. Benefits Quick and easy set-up Determine the gravitational constant g immediately without knowledge of mass or moment of inertia Automatically […]

Mathematical pendulum

Principle A mass, considered as of point form, suspended on a thread and subjected to the force of gravity, is deflected from its position of rest. The period of the oscillation thus produced is measured as a function of the thread length and the angle of deflection. Benefits Quick and easy set-up Automatically measure the […]

Newton’s 2nd law/ demonstration track with Cobra4

Principle According to Newton’s 2nd law of motion for a mass point, the relationship between mass, acceleration and force are investigated. Tasks The distance-time law, the velocity time law and the relationship between mass, acceleration and force are determined. The conservation of energy can be investigated. Benefits Accurate results due to measurements with low friction: […]

Surface tension of liquids

PrincipleThe cohesive forces in a liquid generate tension on its surface, the so-called surface tension. A metal ring that is plunged into a liquid is withdrawn from the liquid. At a certain tensile force, the liquid film will be disrupted from the ring. Based on the tensile force and ring diameter, the surface tension of […]

Surface tension with the ring method (Du Nouy method)

Principle The force is measured on a ring shortly before a liquid film tears using a torsion meter. The surface tension is calculated from the diameter of the ring and the tear-off force. Benefits High sensitivity measurement possible thanks to ring method Analogue set-up that can also be used as a demo experiment in the lecture […]

Viscosity measurement with the falling ball viscometer

Principle Due to internal friction among their particles, liquids and gases have different viscosities. The viscosity, a function of the substance’s structure and its temperature, can be experimentally determined, for example, by measuring the rate of fall of a ball in a tube filled with the liquid to be investigated. Benefits Viscosity measurement for two […]

Viscosity of Newtonian and non-Newtonian liquids (rotary viscometer)

PrincipleThe viscosity of liquids can be determined with a rotation viscometer, in which a motor with variable rotation speed drives a cylinder immersed in the liquid to be investigated with a spiral spring. The viscosity of the liquid generates a moment of rotation at the cylinder which can be measured with the aid of the […]

Density of liquids

Principle The density of water and glycerol is determined as a function of temperature using the Mohr balance. Benefits Mohr density balance enables high-precision measurements Interdisciplinary use also in applied sciences or physical chemistry Tasks The density of water and glycerol is measured in 1 to 2 °C steps over a temperature range from 0 […]

Mechanical conservation of energy/ Maxwell’s wheel

Principle A disc, which can unroll with its axis on two cords, moves in the gravitational field. Potential energy, energy of translation and energy of rotation are converted into one another and are determined as a function of time. Benefits High and sturdy set-up Expressive demonstration of energy conversion Convert potential energy in energy of […]

Flow Measurement / Ultrasonic Doppler effect

Principle The aim of this experiment is to study the relationship between the ultrasonic Doppler effect and the flow velocity or the Doppler angle. Benefits Ideal for teaching the basics of the Doppler effect in fluids Experiment setup can be upgraded to perform experiments like flow mechanics and Doppler sonography Compact, easy to understand experiment […]

Mechanics of flow

Principle The ultrasonic Doppler effect is used for studying the laws of steadily and laminarly flowing liquids in a tube circuit, which form the basis of numerous technical applications. The experiment focuses particularly on the relationship between the flow velocity and the cross-sectional tube area (continuity condition) as well as on the relationship between the […]

Surface of rotating liquids

Principle A vessel containing liquid is rotated about an axis. The liquid surface forms a paraboloid of rotation, the parameters of which will be determined as a function of the angular velocity. Benefits Didactical unique Interdisciplinary use also in applied sciences or physical chemistry Tasks On the rotating liquid surface, the following are determined: the […]

Reversible pendulum

Principle By means of a reversible pendulum, terrestrial gravitational acceleration g may be determined from the period of oscillation of a physical pendulum, knowing neither the mass nor the moment of inertia of the latter. Benefits Quick and easy set-up Determine the gravitational constant g immediately without knowledge of mass or moment of inertia Automatically […]

Determination of the gravitational constant/ computerised Cavendish balance

Principle Two small lead spheres are positioned on a beam, which is freely suspended on a thin metal wire. At the beginning the large lead spheres are positioned symmetrically opposite to the small spheres in that way that the attractive forces are eliminated. There after, the large spheres are swung so that they are close […]

Moments of inertia and torsional vibrations

Principle Various bodies perform torsional vibrations about axes through their centres of gravity. The vibration period is measured and the moment of inertia determined from this. Benefits Selection of materials allows demonstrating all aspects of moments of inertia in one experiment Clear and easy set-up Tasks The following will be determined: The angular restoring moment […]

Hooke’s law

PrincipleThe validity of Hooke’s law is determined for two helical springs with different spring constants. The elongation of the helical spring, which depends on the deforming force, is studied by means of the weights of masses. For comparison, a rubber band, for which no proportionality exists between the exerted force and the resulting elongation, is […]

Mechanical hysteresis

Principle The relationship between torque and angle of rotation is determined when metal bars are twisted. The hysteresis curve is recorded. Benefits Beyond Hooke’s law Hysteresis – mostly known from the field of magnetism – can be experienced in mechanics Learn the meaning of the words stress, relaxation and equilibrium in a physics context Various […]

Modulus of elasticity / Youngs Modulus

Principle A flat bar is supported at two points. It is bent by the action of a force acting at its centre. The modulus of elasticity is determined from the bending and the geometric data of the bar. Benefits Find out the parameters that give a bar stability Measure the difference of elasticity in various […]

Moments

Principle Coplanar forces (weight, spring balance) act on the moments disc on either side of the pivot. In equilibrium, the moments are determined as a function of the magnitude and direction of the forces and of the reference point. Benefits Understand the relation and the difference between moments and force. Smart designed equipment that makes […]

Moments of inertia of different bodies/ Steiner’s theorem with Cobra4

Principle The moment of inertia of a solid body depends on its mass distribution and the axis of rotation. Steiner’s theorem elucidates this relationship. Benefits Angular oscillation apparaturs includes five different body shapes for in-depth experimenting High-precision movement sensor Very robust and durable setup Tasks The moments of inertia of different bodies are determined by […]

Laws of gyroscopes/ cardanic gyroscope

Principle If the axis of rotation of the force-free gyroscope is displaced slightly, a nutation is produced. The relationship between precession frequency or nutation frequency and gyro-frequency is examined for different moments of inertia. Additional weights are applied to a gyroscope mounted on gimbals, so causing a precession. Benefits Unique set-up of the Magnus-type gyroscope […]

Mechanical conservation of energy/ Maxwell’s wheel with measure Dynamics

Principle A wheel, which can unroll around its axis on two cords, moves a gravitational field. This process is filmed with a video camera. The potential energy, kinetic energy, and rotational energy are converted into one another and determined as a function of time with the aid of the “measure Dynamics” software. Benefits High and […]

Laws of gyroscopes/ 3-axis gyroscope

Principle The momentum of inertia of the gyroscope is investigated by measuring the angular acceleration caused by torques of different known values. In this experiment, two of the axes of the gyroscope are fixed. The relationship between the precession frequency and the gyro-frequency of the gyroscope with 3 free axes is examined for torques of […]

Centrifugal force

Principle A body with variable mass moves on a circular path with adjustable radius and variable angular velocity. The centrifugal force of the body will be measured as a function of these parameters. Benefits Easy to read measures Several loadable weights enable variable set-up Freely set various steady rotational velocities Tasks Determination of the centrifugal […]

Moment of inertia and angular acceleration with a precision pivot bearing

Principle A moment acts on a body which can be rotated about a bearing without friction. The moment of inertia is determined from the angular acceleration. Benefits Long runtime Nearly friction-less movement due to precision bearing and precision pulley Steady set-up prevents interferences Tasks From the angular acceleration, the moment of inertia is determined as […]

Moment of inertia and angular acceleration with Cobra4 and a precision pivot bearing

Principle If a constant torque is applied to a body that rotates without friction around a fixed axis, the changing angle of rotation increases proportionally to the square of the time and the angular velocity proportional to the time. Benefits Long runtime Nearly friction-less movement due to precision bearing Steady set-up prevents interferences Data logging […]

Laws of collision/ demonstration track with a 4-4 timer

Principle The volocities of two gliders, moving without friction on a demonstration track, are measured before and after collision, for both elastic and inelastic collision. Tasks Elastic collision The impulses of the two gliders as well as their sum after the collision. For comparison the mean value of the impulses of the first glider is […]

Ballistic pendulum

Principle A classic method of determining the velocity of a projectile is to shoot it into a resting mass hung as a pendulum. The projectile remains in the pendulum and swings with it. This is an inelastic collision in which the momentum remains unchanged. The velocity of the pendulum’s mass (including the projectile’s mass) at […]

Projectile motion with measure Dynamics

Principle A steel sphere is launched by a ballistic unit and the resulting trajectory is filmed with the aid of a video camera. The “measure Dynamics” software is used to demonstrate the dependence of the trajectory on the launching angle and on the initial velocity, and to determine the range and height of the trajectory. In […]

Projectile motion

Principle A steel ball is fired by a spring at different velocities and at different angles to the horizontal. The relationships between the range, the height of projection, the angle of inclination and the firing velocity are determined. Benefits Learn a classic method to determine a projectile’s velocity See how to utilize conservation laws for […]

Free fall with measure Dynamics

Principle The aim of this experiment is to film a high-speed video of a sphere falling from the height of fall h. The “measure Dynamics” software is used for the graphical representation of the distance as a function of time t and also as a function of the square of time t^2 as well as the graphical representation of […]

Free Fall with timer 2-1

PrincipleA sphere falls freely over certain distances. The falling time is measured and evaluated from diagrams. The acceleration due to gravity can be determined. Benefits Gravitation scrutinized Find out how the velocity of a falling object increases Didactical demonstration of the falling distances Visualise the squared distance-time law Steady set-up All crucial parts directly engineered […]

Free fall with Cobra4

Principle The fall times t are measured for different heights of fall h. h is represented as the function of t or t², so the distance-time law of the free fall results as h = 1/2 · g · t². Then the measured values are taken to determine the acceleration due to gravity g. Benefits […]

Newton’s 2nd law/ demonstration track with measure Dynamics

Principle A mass, which is connected to a cart via a silk thread, drops to the floor. The resulting motion of the cart will be recorded by way of a video camera and evaluated with the “measure Dynamics” software. The relationship between distance and time, velocity and time, and the relationship between mass, acceleration, and force […]

Newton’s 2nd law/ demonstration track

Principle The distance-time law, the velocity time law, and the relationship between mass, acceleration and force are determined with the aid of the demonstration track rail for uniformly accelerated motion in a straight line. Tasks Determination of: Distance travelled as a function of time Velocity as a function of time Acceleration as a function of […]

Basic measurement techniques

Principle Caliper gauges, micrometers and spherometers are used for the accurate measurement of lengths, thicknesses, diameters and curvatures. Measuring procedures, accuracy of measurement and reading accuracy are demonstrated. Benefits Foundation of every practical sciences lab course Aquire the skills to measure basic mechanical variables Realise the limits of measuring accuracy Combine different measurements to determine […]