Question

An ac source is of $\frac{200}{\sqrt{2}}V$, $50Hz$ . The value of voltage after $\frac{1}{600}s$ from the start is

• A. $200V$
• B. $\frac{200}{\sqrt{2}}V$
• C. $100V$
• D. $50V$

Answer 1

Answer: (C)

$V_m=\frac{200}{\sqrt{2}}{V}_{rms}$
$V_0=\sqrt{2}{V}_{rms}=\sqrt{2}\times \frac{200}{\sqrt{2}}=200V$
$V=V_{0}sin2\pi \upsilon t=200sin\left(2\pi \times 50\times \frac{1}{600}\right)$
$=200sin\frac{\pi }{6}=200\times \frac{1}{2}=100V$