Question

A parallel plate capacitor is charged and the charging battery is then disconnected. If the plates of the capacitor are now moved apart by means of insulting handles :

• A. the charge on capacitors increases
• B. the voltage across the capacitors decreases
• C. the capacitance increases
• D. the electrostatic energy stored in the capacitor increases

Answer 1

The correct option is D the electrostatic energy stored in the capacitor increases

Energy stored in a capacitor is given by:-

$W=\frac{Q^2}{2C}$

The capacitance of a parallel plate capacitor is given by:

$C=\frac{Aϵ}{d}$

d-distance between plates

So, if d is increased C decreases and hence W increases.