Conductors and Capacitors

What is the primary function of a capacitor in an electrical circuit?

Which of the following relationships between capacitance $C$, charge $Q$, and voltage $V$ is correct?

A parallel-plate capacitor has a plate area of 0.01 $m^2$ and a separation of 0.001 m. If the dielectric constant is 1, what is the capacitance?

A parallel-plate capacitor has an initial capacitance $C$. If the plate area is doubled and the plate separation is also doubled, what is the new capacitance?

A parallel-plate capacitor has a charge $Q$ on its plates and an area $A$. What is the electric field $E$ between the plates?

A parallel plate capacitor has charge $Q$ and area $A$. If the charge is doubled, what happens to the electric field between the plates?

How does the energy stored in a capacitor change if the voltage across it is doubled, assuming the capacitance remains constant?

A 2 $\mu$F capacitor is charged to a potential difference of 10 V. How much energy is stored in the capacitor?

A parallel-plate capacitor has a capacitance $C$ and a voltage $V$ across its plates. What is the energy density (energy per unit volume) in the capacitor?

A parallel-plate capacitor is connected to a voltage source. What happens to the capacitance, charge, and voltage when a dielectric material is inserted between the plates while the capacitor remains connected to the voltage source?