Question

A charge of 25 C is moved from infinity to points A and B in an electric field when the work is done to do so is 10 J and 10.5 J respectively. Calculate the potential difference between points A and B.

Answer 1

W_A = 10 J 

Charge Q = 25 C

Potential at point A = V₁ = `"W"_"A"/"Q"`

V₁ = `10/25 = 0.4` V

Also, W_B = 10.5 J

Potential at point B = V₂ = `"W"_"B"/"Q"`

V₂ = `10.5/25 = 0.42` volt

A potential difference between A and B = V

V = V₂ - V₁ 

V = 0.42 - 0.40

V = 0.02 volt