Energy Stored in Capacitor — MCQ Practice

A parallel plate capacitor has capacitance $C$. It is charged to a potential $V$ by a battery. The battery is then disconnected, and a dielectric slab of dielectric constant $K$ is inserted between the plates. What is the new energy stored in the capacitor?

Two capacitors of capacitances $C_1 = 2,mu F$ and $C_2 = 3,mu F$ are charged to potentials $V_1 = 100,\text{V}$ and $V_2 = 50,\text{V}$ respectively. They are then connected in parallel with plates of like polarity joined together. Calculate the energy lost during the connection.

A parallel plate capacitor has an area $A$ and plate separation $d$. It is charged by a battery to a potential $V$. The energy stored in the capacitor is $U_0$. If the plate separation is doubled to $2d$ while the battery remains connected, what is the new energy stored?

A capacitor of $10,mu F$ is charged to $200,\text{V}$. How much energy is stored in it?

The electric field between the plates of a parallel plate capacitor is $E$. If the area of the plates is $A$ and the separation is $d$, what is the energy density stored in the electric field?

A capacitor is charged by a battery. The work done by the battery is $W_B$. The energy stored in the capacitor is $U$. What is the relationship between $W_B$ and $U$?