Question

In an ac circuit, the instantaneous current is zero,when the instantaneous voltage is maximum. In this case, the source may be connected to :
A. pure inductor.
B. pure capacitor.
C. pure resistor.
D. combination of an inductor and capacitor.
Choose the correct answer from the options given below :

• A. A, B and C only
• B. B, C and D only
• C. A and B only
• D. A, B and D only

Answer 1

The Correct Option is D

AC Circuit Phase Relationships:
In AC circuits: current \( I \) lags voltage \( V \) by \( 90^\circ \) (\( \frac{\pi}{2} \) radians) in a pure inductor.
In a pure capacitor, current \( I \) leads voltage \( V \) by \( 90^\circ \). In a pure resistor, current and voltage are in phase, reaching zero and maximum values simultaneously.

Condition: Instantaneous Current is Zero When Voltage is Maximum:
 This condition signifies a \( 90^\circ \) phase difference between current and voltage.
This occurs in:
- Pure inductors (current lags voltage by \( 90^\circ \)).
- Pure capacitors (current leads voltage by \( 90^\circ \)).
- LC circuits (inductor-capacitor combinations), where the phase difference can also lead to zero current at maximum voltage.

Conclusion:
This phase relationship is observed in pure inductors, pure capacitors, and LC combinations. Therefore, the correct answer is Option (4): A, B, and D only.