Question

How does the amount of work needed to move this charge compare for these three cases ?

• A. Most work required in I
• B. Most work required in II
• C. Most work required in III
• D. I and II required the same amount of work but less than III
• E. All three would require the same amount of work

Answer 1

The correct option is E All three would require the same amount of work

Given that charged particle of charge $+1\mu C$ is moved from point $A$ to $B$ along equipotential surface. We have to find the amount of work needed to move this charge compare for these three cases.

Since work done in moving $+1\mu C$ charge is equal to product of charge and the change in potential from moving a charge from point $A$ to $B$.

Work done $=+1\mu C\times (V_B-V_A)$

Since $V_B=400$

$V_A=200$

and $V_B-V_A=40-20=20V$ is same for all these three cases. So the work done is also same for these cases.