Question

An electric lamp is connected in series with a capacitor and an AC source is glowing with a certain brightness. How does the brightness of the lamp change on increasing the capacitance?

Answer 1

Capacitive reactance:

`"X"_"C" = 1/(2pi"fC")`

The capacitive reactance is inversely proportional to the capacitance. The capacitive reactance decreases as the capacitance increases. The current flow increases as capacitive reactance decreases. The brightness is proportional to the magnitude of the current, therefore the brightness of the bulb increases as the current increases. Therefore it can be concluded that the brightness of the bulb increases as the capacitance increases.