Question

The power factor of the circuit as shown in figure is

• A. 0.2
• B. 0.4
• C. 0.8
• D. 0.6

Answer 1

Answer: (C)

0.8

Answer 2

: Resistance of circuit,

$\mathrm { R } = \mathrm { R } _ { 1 } + \mathrm { R } _ { 2 } = 40 \Omega + 40 \Omega = 80 \Omega$

Impedance of the circuit,

$\mathrm { Z } = \sqrt { \mathrm { R } ^ { 2 } + \left( \mathrm { X } _ { \mathrm { L } } - \mathrm { X } _ { \mathrm { C } } \right) ^ { 2 } } = \sqrt { ( 80 ) ^ { 2 } + ( 100 - 40 ) ^ { 2 } }$

$= \sqrt { ( 80 ) ^ { 2 } + ( 60 ) ^ { 2 } } = 100 \Omega$

Power factor,