Question

In which of the following circuit do we find the current and voltage in phase?

• A. A purely resistive circuit
• B. A circuit in which an inductor and a capacitor are in series.
• C. A purely inductive circuit
• D. A purely capacitive circuit

Hint:

Resistor → in phase, Inductor → current lags, Capacitor → current leads.

Answer 1

The Correct Option is A

Step 1: Understand phase relation.
In AC circuits, current and voltage may not be in phase.

Step 2: Pure resistive circuit.
In resistor:
\[ V \propto I \]
Thus, current and voltage are in phase.

Step 3: Inductive circuit behavior.
Current lags voltage by \( 90^\circ \).

Step 4: Capacitive circuit behavior.
Current leads voltage by \( 90^\circ \).

Step 5: LC circuit.
Phase difference exists depending on reactance.

Step 6: Conclusion.
Only purely resistive circuit has zero phase difference.

Step 7: Final Answer.
\[ \boxed{\text{Purely resistive circuit}} \]