Question

Two large oppositely charged insulated plates have a uniform electric field between them as shown. The distance between the plates is increased by a small amount. Which of the following statements is/are correct ?
Statement $\left(i\right)$ The electric field strength decreases
Statement $\left(ii\right)$ The electrostatic force of attraction between the plates increases
Statement$\left(iii\right)$ The potential difference between the plates increases

• A. $\left(i\right)$ only
• B. $\left(ii\right)$ only
• C. $\left(iii\right)$ only
• D. $\left(i\right)$ and $\left(iii\right)$ only

Answer 1

Answer: (C)

$\left(iii\right)$ only

Since charge and charge density on plate remains constant, electric field between the plates does not change due to increase in separation of plates.
Now charge on one plate and electric field in its surroundings does not change, therefore magnitude of electrostatic force on that plate remains constant.
Only the electrostatic potential difference between the plates increases as a result of increase in their separation.