Question

Figure shows an electric line of force which curves along a circular arc. The magnitude of electric field intensity is same at all points on this curve and is equal to E. If the potential at A is V, then the potential at B is:

• A. $V-ER\theta$
• B. $V-2ERsin\frac{\theta }{2}$
• C. $V+ER\theta$
• D. $V+2ERsin\frac{\theta }{2}$

Answer 1

The correct option is B $V-2ERsin\frac{\theta }{2}$

In the given figure.

Distance between $AB$

$d=2R\sin \frac{\theta }{2}$

change in potential $=V-2Ed$

$=V-2ER\sin \frac{\theta }{2}$

Hence,

option $\left(B\right)$ is correct answer.