Question

Two large oppositely charged insulated plates have a uniform electric field between them. The distance between the plates is increased. Which of the following statements is true?

I. The field strength decreases.

II. The field strength increases.

III. The potential difference between the plates increases.

(A) I only 

(B) II only 

(C) III only 

(D) I and III only 

(E) II and III only

Answer 1

The correct option is: (C) III only 

Explanation :

Since the plates are insulated, the charge remains constant. If the distance is increased, the capacitance will decrease (C ∝ A/d) and since Q = CV, the potential difference must increase by the same factor that the distance increases. This means E = V/d remains the same.