Question

Two large, flat, parallel, conducting plates are 0.04 m apart, as shown above. The lower plate is at a potential of 2 V with respect to ground. The upper plate is at a potential of 10 V with respect to ground. Point P is located 0.01 m above the lower plate.

The electric potential at point P is

(A) 10 V 

(B) 8 V 

(C) 6 V 

(D) 4 V 

(E) 2 V

Answer 1

The correct option is: (D) 4 V 

Explanation:

The electric field between charged parallel plates is uniform, which means the potential changes uniformly with distance. For a change of 8 V over 4 cm means the change of potential with position (and the electric field strength) is 2 V/cm, which gives the potential 1 cm away from the 2 V plate as 4 V