NEETPhysicsAlternating Current
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In a purely capacitive AC circuit, if the frequency of the source is doubled, the peak displacement current between the capacitor plates is also doubled. Reason (R): The capacitive reactance of a capacitor is inversely proportional to the frequency of the AC source. In the light of the above statem
Options
- ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is correct but Reason (R) is not correct.
- DAssertion (A) is not correct but Reason (R) is correct.
Correct answer
A. Both Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
The capacitive reactance is given by X_C = 1 2 f C . This shows that X_C is inversely proportional to the frequency f of the AC source. Thus, Reason (R) is correct. The peak conduction current in the circuit is I_m = V_m X_C = V_m (2 f C) . This means the current is directly proportional to the frequency ( I_m f ). According to Maxwell's equations, the displacement current between the capacitor plates is equal to the conduction current in the connecting wires. Therefore, if the frequency f is doubled, the peak disp