Question 492: AC fundamentals

Question

A coil of inductive reactance 31 $$\Omega $$ has a resistance of 8 $$\Omega $$. It is placed in series with a condenser of capacitative reactance 25 $$\Omega $$. The combination is connected to an a.c. source of 110 V. The power factor of the circuit is

Accepted Answer

Impedance of series LCR is
Z = $$\sqrt {{R^2} + {{\left( {{X_L} - {X_C}} \right)}^2}} $$
= $$\sqrt {{8^2} + {{\left( {31 - 25} \right)}^2}} $$
= $$\sqrt {64 + 36} $$ = 10 $$\Omega $$
Power factor, cos$$\phi $$ = $${R \over Z} = {8 \over {10}} = 0.8$$

Answer

0.33

Answer

0.56

Answer

0.64

Answer

0.80

AC fundamentals

A coil of inductive reactance 31 $\Omega has a resistance of 8 \Omega . It is placed in series with a condenser of capacitative reactance 25 \Omega $. The combination is connected to an a.c. source of 110 V. The power factor of the circuit is

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