A part of a complete circuit is shown in the figure. At some
Question:

A part of a complete circuit is shown in the figure. At some

instant, the value of current $\mathrm{I}$ is $1 \mathrm{~A}$ and it is decreasing at

a rate of $10^{2} \mathrm{~A} \mathrm{~s}^{-1}$. The value of the potential difference $\mathrm{V}_{\mathrm{P}}$

$-\mathrm{V}_{\mathrm{Q}}$, (in volts) at that instant, is

Solution:

(33)

Here, $L=50 \mathrm{mH}=50 \times 10^{-3} \mathrm{H} ; I=1 \mathrm{~A}, R=2 \Omega$

$V_{P}-L \frac{d l}{d t}-30+R I=V_{Q}$

$\Rightarrow V_{P}-V_{Q}=50 \times 10^{-3} \times 10^{2}+30-1 \times 2$

$=5+30-2=33 \mathrm{~V}$