An electron charge 1.6 x 10-19C is accelerated in vacuum from rest at zero volt towards a plate at 40k V. Calculate the kinetic energy of the electron
Answer Details
The work done in accelerating the electron is given by W = qV where q is the charge of the electron and V is the potential difference. The potential difference is given as 40 kV, which is equivalent to 40 x 10^3 V. Therefore, the work done in accelerating the electron is:
W = (1.6 x 10^-19 C) x (40 x 10^3 V) = 6.4 x 10^-15 J
This work done is equal to the kinetic energy gained by the electron since it started from rest. Therefore, the kinetic energy of the electron is:
K.E = 6.4 x 10^-15 J
Hence, the correct option is: 3.2 x 10^-15 J.