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The diagram above illustrates an a.c.source of 50V(r.m.s....

The diagram above illustrates an a.c.source of 50V(r.m.s.), \(\frac{100}{\pi}\)Hz connected in series with an 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

The diagram above illustrates an a.c.source of 50V(r.m.s.), 100πHz connected in series with an 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 is C

cosθ=RZ

R = VI=402=20

Z² = R² + XL² = 20²  + 15²  = √625 = 25

cos θ=RZ=2025=0.8