Question

In a set, a bulb and a capacitor are connected what will happen if we increase the frequency?

Answer 1

Capacitor:

1. A capacitor is a system of conductors and dielectrics, which can store electric charge.
2. Usually, it consists of a pair of conductors containing equal and opposite charges $\left(\pm Q\right)$ with a potential difference $\left(V\right)$ between them, which is independent of the presence of other conductors.
3. The total charge of a capacitor system is zero but by convention, the charge on the positive conductor is called the charge on the capacitor.
4. The potential difference $\left(V\right)$ between the conductors is proportional to the charge on the capacitor.
5. This can be written as $Q=CV$ where $C$ is called the capacitance of the capacitor.
6. One farad is the capacitance of a capacitor, which requires $1C$ charge to establish a potential difference of one volt across it.

Relation with frequency

1. The reactance of a capacitor is inversely proportional to the frequency of the AC circuit.
2. This means that, when the frequency of the AC circuit is increased, its capacitive reactance will decrease.
3. We know that current is also inversely proportional to the capacitive reactance.
4. Therefore the current flow will increase.
5. Hence, more current will reach the bulb through the capacitor, and the bulb will glow more brightly.