A proton when released from point A moves to a point B in an electric field. Which of A and B is at a higher potential ? Explain.
If the potential difference between the points A and B is 5 V, find the amount of work done in moving a proton from B to A
(Take charge of proton as `+1.6 xx 10^(-19)C`).

Explanation

The charge of proton, `Q = +1.6 xx 10^(-19)C`
The proton moves from Q to B, the point A is at higher potential than point B.
The P.D. between A and B is 5V.
We know
`V_(A) = (w)/(q) rArr w = V xx q = 5V xx 1.6 xx 10^(-19)C = 8 xx 10^(-19)J`