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

Assessment: WAEC SSCE - Physics - 1991 (Objective) Subject: Physics

Question 1 Report

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

4.0 x 10^-26J

4.0 x 10^-21J

6.4 x 10^-20J

3.2 x 10^-15J

2.5 x 10^-20J

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.

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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

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