Question

The impedance of a circuit consists of 3 ohm resistance and 4 ohm reactance. The power factor of the circuit is

• A. 0.4
• B. 0.6
• C. 0.8
• D. 1.0

Answer 1

Answer: (B)

0.6

Answer 2

$Z = \sqrt { R ^ { 2 } + X ^ { 2 } } = \sqrt { 4 ^ { 2 } + 3 ^ { 2 } } = 5$

$\therefore \cos \phi = \frac { R } { Z } = \frac { 3 } { 5 } = 0.6$