Question

Power factor can be improved by installing a device in parallel with load which has :

• A. Leading reactive power
• B. Lagging reactive power
• C. Apparent power
• D. Resistive power

Hint:

Power factor correction devices:
• Capacitor bank
• Synchronous condenser Both provide: \[ \text{Leading Reactive Power} \]

Answer 1

The Correct Option is A

Concept: Most industrial loads are inductive in nature and therefore consume: \[ \text{Lagging reactive power} \] This causes poor power factor. Power factor improvement is achieved by supplying: \[ \text{Leading reactive power} \] using devices such as capacitors or synchronous condensers.

Step 1: Understanding poor power factor. Inductive loads such as:
• induction motors,
• transformers,
• reactors draw lagging current. Hence: \[ \cos\phi \] becomes low.

Step 2: Understanding reactive power compensation. To improve power factor: \[ \text{Lagging VARs must be cancelled} \] This is achieved using: \[ \text{Leading VARs} \]

Step 3: Role of capacitor bank. Capacitors provide: \[ Q_C = V^2\omega C \] which is leading reactive power. When connected in parallel:
• capacitor current leads voltage,
• net reactive current reduces,
• overall power factor improves.

Step 4: Analyzing the options.
• Leading reactive power \(\rightarrow\) Correct
• Lagging reactive power \(\rightarrow\) worsens PF
• Apparent power \(\rightarrow\) not compensation quantity
• Resistive power \(\rightarrow\) incorrect terminology

Step 5: Selecting the correct answer. Thus correct option is: \[ \boxed{(1)} \]