Aim - To investigate the
path of the electron beam in a cathode ray tube.
Instructions
Note the value of the EHT voltage used in the electron gun.
Calculate the work done on each electron by the electric field in the electron gun.
Hence calculate the speed of the electrons as they leave the electron gun and enter the
evacuated tube.
Switch the HT supply ON. Sketch the path followed by the electron beam as it
passes between the deflection plates when:
a) bottom plate is positive, top plate is negative
b) top plate is positive, bottom plate is negative
Explain the effect the following changes have on the path followed by the electron beam:
a) increase EHT voltage on the electron gun
b) increase HT voltage on the deflection plates.