Question

An alternating e.m.f. $e=220\sin \left(120\pi t\right)$volt is applied to a bulb of resistance $110\Omega$. Find peak value, effective value, frequency and period of alternating current through bulb.

Answer 1

Given $e=220\sin \left(120\pi t\right)$ .....(i)
$R=110\Omega$
$e=e_0\sin \omega t$ .....(ii)
Comparing (i) and (ii) $e_0=220$volt, $\omega =120\pi$
$i_0=\frac{e_0}{R}=\frac{220}{110}=2$
$i_0=2$Amp.
$i_{rms}=\frac{I_0}{\sqrt{2}}=\frac{2}{\sqrt{2}}=1.414$Amp.
$\omega =2n\pi =120\pi$
$n=60Hz$.
$T=\frac{1}{n}=\frac{1}{60}=0.0166$sec.