The power factor of the circuit as shown in figure is

Options

A. `0.2`
B. `0.4`
C. `0.8`
D. `0.6`

Answer

C

Explanation

Resistance of the circuit,
`R=R_(1)+R_(2)=40 Omega + 40 Omega=80 Omega`
Impedance of the circuit,
`Z=sqrt(R^(2)+(X_(L)-X_(C ))^(2))=sqrt((80)^(2)+(100-40)^(2))`
`sqrt((80)^(2)+(60)^(2))=100 Omega`
Power factor, `cos phi = (R )/(Z)=(80)/(100)=0.8`