The problem states that an alternating current circuit has an impedance of 50 ohms and a resistance of 20 ohms. We need to find the power factor of the circuit.

1. Problem Description

The problem states that an alternating current circuit has an impedance of 50 ohms and a resistance of 20 ohms. We need to find the power factor of the circuit.

2. Solution Steps

The power factor (PF) is defined as the ratio of the resistance (R) to the impedance (Z) in an AC circuit.

$PF = \frac{R}{Z}$

Given:

Resistance, $R = 20 \, \text{ohms}$

Impedance, $Z = 50 \, \text{ohms}$

Substitute the given values into the formula:

$PF = \frac{20}{50}$

$PF = \frac{2}{5}$

$PF = 0.4$

3. Final Answer

The power factor of the circuit is 0.

4. The correct answer is A. 0.4.