In an a.c. circuit the instantaneous current and emf are represented as $I=I_0, \sin [\omega t-\pi / 6]$ and…
In an a.c. circuit the instantaneous current and emf are represented as $I=I_0, \sin [\omega t-\pi / 6]$ and $\mathrm{E}=\mathrm{E}_0 \sin [\omega \mathrm{t}+\pi / 3]$ respectively. The voltage leads the current by
$\frac{\pi}{2}$
$\frac{\pi}{4}$
$\frac{\pi}{3}$
$\frac{\pi}{6}$
Solution
Given $\phi_1=\frac{\pi}{6}$ and $\phi_2=\frac{\pi}{3}$
$\therefore \quad \Delta \phi=\frac{\pi}{3}-\left(\frac{-\pi}{6}\right)=\frac{\pi}{2}$