Question

A capacitor has some dielectric between its plates, and the capacitor is connected to a dc source. The battery is now disconnected and then the dielectric is removed, then

• A. capacitance will increase
• B. energy stored will decrease
• C. electric field will increase
• D. voltage will decrease

Answer 1

Answer: (C)

When the capacitor is connected to $dc$ source, it gets charged. The battery is then disconnected, so no more charge can flow in. On removing dielectric, capacitance decreases
Energy stored $\left(u=\frac{q^2}{2C}\right)$ will increase
Potential $\left(V=\frac{q}{C}\right)$ will also increase
Electric field $\left(E=\frac{V}{D}\right)$ will increase