Question

Figure shows some equipotential lines distributed in space. A charged object is moved from point A to point B.

• A. The work done in figure (i) is the greatest.
• B. The work done in figure (ii) is the least.
• C. The work done is the same in figure (i), (ii) and (iii).
• D. The work done is the same in figure (iii) is greater than figure (ii) but equal to that in figure (i).

Answer 1

Answer: (C)

The work done is the same in figure (i), (ii) and (iii).

In all the three figures, $V_A=20V$ and $V_B=40V$
Work done in carrying a charge $q$ from $A$ to $B$ is
$W=q(V_B-V_A)$
Hence the work done is same in all figures.