Question

To a highly inductive circuit, a small capacitance is added in series. The angle between voltage and current will,

• A. increase
• B. decrease
• C. remain nearly same
• D. become indeterminant

Hint:

In series AC circuits, inductive and capacitive reactances oppose each other. Adding capacitance to an inductive circuit always reduces the phase angle.

Answer 1

The Correct Option is B

Step 1: Understand the nature of a highly inductive circuit.
In a highly inductive circuit, the current lags the voltage by a large angle because the inductive reactance dominates over resistance.
Step 2: Effect of adding a capacitor in series.
When a capacitor is added in series, it introduces capacitive reactance which opposes the inductive reactance.
This reduces the net reactive component of the circuit impedance.
Step 3: Effect on phase angle.
The phase angle between voltage and current depends on the ratio of net reactance to resistance.
Since the net reactance decreases due to partial cancellation of inductive reactance by capacitive reactance, the phase angle also decreases.
Step 4: Conclusion.
Therefore, adding a small capacitance in series with a highly inductive circuit causes the angle between voltage and current to
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