Question

The variation of potential with distance R from a fixed point is as shown below. The electric field at R = 5m is

• A. 2.5 volt/m
• B. - 2.5 volt/m
• C. $\frac{2}{5}$ volt/m
• D. $-\frac{2}{5}$ volt/m

Answer 1

The correct option is A 2.5 volt/m

Intensity at 5m is same as at any point between B and C because the slope of BC is same throughout (i.e., electric field between B and C is uniform). Therefore electric field at R = 5m is equal to the slope of line BC hence by $E=\frac{-dV}{dr}$;
$E=-\frac{(0-5)}{6-4}=2.5\frac{V}{m}$