Question

The answer for this question is d; however, I thought it was c. Can someone explain why the answer is d and not c?

15) Which equipotential surfaces better correspond to this electric field? E 40 V 0 V 0 V 40 V 0 V 40 V 0 V 40 V 40 V O V 40 V O V

Answer 1

The relation between electric field and electric voltage is given by the following formula:

$E = -\frac{\Delta V}{\Delta x}$

So we can see here the following points:

1. The magnitude of electric field is inversely proportional to the gap between two equipotential lines and directly proportional to the potential difference between two lines.
2. The direction of the electric field is given by the opposite direction of which the potential is decreasing.

Here to the left the magnitude of electric field is greater than that of the right so the equipotential lines must be closer towards the left and sparse towards the right.

Hence option d is correct.