Question

1 electron volt= __________ J.

(a) 1.6*10^-19

(b) 4.8*10^-19

(c) 1.6*10^-10

(d) 10

The question was asked in an international level competition.

This interesting question is from Electrostatic Potential topic in division Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

The correct choice is (a) 1.6*10^-19

For explanation I would say: 1 electron volt is the amount of work done if an electron is passed through a potential difference of 1V. Therefore the work done = 1V*charge of an electron = 1.602*10^-19 J. But it is a small quantity and hence we use kilo electron volt and mega electron volt in practical.