PURPOSE: To show an electron beam.
DESCRIPTION: Cathode ray tube, as shown. A cathode ray tube produces a beam of electrons which can be seen as it hits a phosphorescent surface inside the tube. Holding a magnet close to the CRT parallel to the table so that it produces a horizontal magnetic field inside the tube causes the electron beam to deflect up or down. The vector nature of the force can be studied by reversing the magnet.
Inside the tube is a pair of parallel electric plates. A voltage can be applied to the plates to deflect the electron beam.
EQUIPMENT: Cathode ray tube, as photographed.
SETUP NOTES: None. The older version of this device is shown below:
Updated by Jun Qi in 3/20/2000