In the electron gun pictured, a potential difference of 12.9 kV is found to brin
ID: 2163713 • Letter: I
Question
In the electron gun pictured, a potential difference of 12.9 kV is found to bring electrons from rest at the cathode to 6.7 107 m/s at the anode. If the electrons reach the anode with a speed of 2.9 107 m/s, what is the potential difference between the cathode and the anode? kV
Electron Plates for gun horizontal deflection (B) Plates for vertical deflection Heated filament (source of electrons) Cathode Uniform E field Electron beam seen from side Cathode Conductive coating Anode Side view Fluorescent screenExplanation / Answer
Voltage accelerates the electrons, hence by using work energy equation we can find out the Potential difference.
Work Done by Electrical Force = Change in Kinteic Energy
q V = 0.5 x m (Vf2 - Vi2)
Vi = 0
1.6 x 10-19 x V = 0.5 x 9.1 x 10-31 x (2.9 x 107)2
V = 2391.59 V
= 2.39 kV