Question

How can the capacitance of an air-filled charged capacitor be increased?

1) By increasing the area of the plates
2) By decreasing the distance between the plates
3) By increasing the dielectric constant of the material between the plates
4) By increasing the charge on the plates

Answer 1

To increase the capacitance of an air-filled capacitor, one can increase the plate area, decrease the plate distance, or introduce a dielectric with a higher dielectric constant. The capacitance is not zero if the plates are uncharged, and uneven plate sizes will result in unequal charge distribution.

Step-by-step explanation:

To increase the capacitance of an air-filled charged capacitor, several methods can be applied. Firstly, by increasing the area of the plates, you can store more charge and therefore increase the capacitance. Secondly, by decreasing the distance between the plates, the electrostatic attraction between the opposing charges on the plates is increased, which also increases capacitance. Thirdly, the introduction of a dielectric material with a higher dielectric constant than air will increase capacitance because it reduces the electric field strength inside the capacitor, allowing for a larger charge to be stored for the same voltage, or similarly, reducing the voltage for the same amount of stored charge, leading to an increase in capacitance.

Regarding the additional questions:

1. The statement that capacitance is zero if the plates are not charged is false. Capacitance is a measure of a capacitor's ability to store charge, not the charge itself.
2. If the plates of a capacitor have different areas and the capacitor is connected across a battery, they will not acquire the same charge. The charge distribution will be uneven due to the differing plate areas.