The diagram below illustrates an a.c.source of 50V(r.m.s.), \(\frac{100}{\pi}\)Hz connected in series with an inductor of inductor of inductance L and a resistor of resistance R. The current in the circuit is 2A and the p.d across L and R are 30V and 40V respectively. Calculate the power factor of the circuit
A. 1.33 B. 1.25 C. 0.80 D. 0.75 E. 0.60
Correct Answer: E
Explanation
cos\(\theta = \frac{R}{Z}\) R = \(\frac{V}{I} = \frac{40}{2} = 20\) Z = R2 + \(^X_L\) = 202 + 152 = 300 cos \(\theta = \frac{R}{Z} = \frac{20}{300} = 0.06\)
