Q.

A capacitor of reactance 43Ω and a resistor of resistance 4Ω are connected in series with an AC source of peak value 82V. The power dissipation in the circuit is ______ W.              [2024]


Ans.

(4)

Z=R2+(XL)2=42+(43)2=8Ω

Vrms=V2=822=8V

Irms=VrmsZ=88=1A

Power dissipation  P=VrmsIrmscosϕ

cosϕ=RZ=4(43)2+42=448+16=48=12

 P=8×1×12=4W