Q. If an alternating voltage is represented as $E = 141\sin{(628\ t),}$ then the rms value of the voltage and the frequency are respectively
A) 141 V, 628 Hz
B) 100 V, 50 Hz
C) 100 V, 100 Hz
D) 141 V, 100 Hz
Explanation
(c) $\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ E = 141\sin{628t}$
$\therefore\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ E_{rms} = \frac{E_{0}}{\sqrt{2}}$
$= \frac{141}{1.41} = 100\ V$
and $v = \frac{\omega}{2\pi}$
$= \frac{628}{2 \times 3.14} = 100\ Hz$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.