Hall effect in p-germanium with Cobra3

Item no.: P2530111 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

Characteristic X-rays of copper

Item no.: P2540101 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

Electron spin resonance

Item no.: P2511200 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

Franck-Hertz experiment with a Hg-tube

Item no.: P2510311 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. Tasks To record the countercurrent strength Ι in a Franck-Hertz tube as a function of the anode voltage U. To

Specific charge of the electron – e/m

Item no.: P2510200 Principle Electrons 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

Polarisation through quarter-wave plates with optical base plate

Item no.: P2250105 Principle Monochromatic light impinges on amica plate, perpenicularly to its optical axis. If the thickness of the plate is adequate (lambda/4 plate), a phase shift of 90° occurs between the ordinary and the extraordinary beam when the latter leaves the crystal. The polarisation of exiting light is examined for different angles between

Ferromagnetic hysteresis with Cobra4

Item no.: P2430760 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. Tasks Record the hysteresis curve

Coupled resonant circuits

Item no.: P2450201 Principle The Q factor of oscillating circuits is determined from the band width and by the Pauli method. In inductively coupled circuits (band-pass filters) the coupling factor is determined as a function of the coil spacing. Tasks Determine the dissipation factor t and k and the quality factor Q from the band