Question

Expressions for e.m.f- and current in A.C. circuit are $ E=200sin\text{ }314\text{ }t $ volt and $ I=100\,\sin \,\left( 314t+\frac{\pi }{3} \right)A, $ the power factor will be:

• A. $ 1/2 $
• B. $ 1/4 $
• C. $ 1 $
• D. $ -1 $

Answer 1

Answer: (A)

$ E=200\,\sin \,314\,t $ $ I=100\,\,\sin \left( 314t+\frac{\pi }{3} \right) $ Phase difference $ \phi =\frac{\pi }{3} $ Power factor $ \cos \phi =\cos \frac{\pi }{3}=\frac{1}{2} $