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)

Electric field will increase.

Answer 2

: 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