Alternating Current Question 12
Question 12 - 2024 (31 Jan Shift 2)
An AC voltage $\mathrm{V}=20 \sin 200 \pi \mathrm{t}$ is applied to a series LCR circuit which drives a current
$\mathrm{I}=10 \sin \left(200 \pi \mathrm{t}+\frac{\pi}{3}\right)$. The average power dissipated is:
(1) $21.6 \mathrm{~W}$
(2) $200 \mathrm{~W}$
(3) $173.2 \mathrm{~W}$
(4) $50 \mathrm{~W}$
Show Answer
Answer: (4)
Solution:
$<\mathrm{P}\rangle=\mathrm{IV} \cos \phi$
$=\frac{20}{\sqrt{2}} \times \frac{10}{\sqrt{2}} \times \cos 60^{\circ}$
$=50 \mathrm{~W}$
