Q. The voltage of an ac supply varies with time $(t)$ as $V = 120\sin{100\pi t}\cos{100\pi t}$. The maximum voltage and frequency respectively are
A) $12\ volts,\ 100\ Hz$
B) $\frac{120}{\sqrt{2}}\ volts,\ 100\ Hz$
C) $60\ volts,\ 200\ Hz$
D) $60\ volts,\ 100\ Hz$
Explanation
(d) $V = 120\sin{100\pi t}\cos{100\pi t} \Rightarrow V = 60\sin{200\pi t}$
$V_{\max} = 60V$ and $v = 100\ Hz$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.