Assertion: An electric lamp connected in series with a variable capacitor and `AC` source, its brightness increases with increases in capacitance.
Reason: Capacitive reactance decrease with increases in capacitance of capacitor.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false

Answer

A

Explanation

Capacitive reactance `X_(C) = (1)/(omegaC) ` When capacitance (C) increases, the capacitive reactance decreases. Due to decrease in its values, the current in the circuit will increase `(I = (E)/(sqrt(R^(2)+ X_(C)^(2))))` and hence brightness of source (or electric lamp) will also increase.