Test Index

NCERT Class XII Chapter
Alternating Current
Questions With Solutions

© examsnet.com
Question : 9 of 26
Marks: +1, -0
A series LCR circuit with R = 20 Ω, L = 1.5 H and C = 35 μF is connected to a variable-frequency 200 V ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?
Solution:  
Average power transferred to the circuit in one complete cycle at resonance
P = EvIcE_v I_c cos ϕ
P = EvEvZE_v \frac{E_v}{Z} cos ϕ
At resonance Z = R, cos ϕ = cos 0° = 1
P = 200 × 20020\frac{200}{20} = 2000 W
© examsnet.com
Go to Question:
Prev Question
Next Question