Question

The current following through an inductance coil of self inductance $6 \,mH$ at different time instants is as shown. The emf induced between $t =20\, s$ and $t =40\, s$ is nearly

• A. $2 \times 10^{-2} V$
• B. $3 \times 10^{-4} V$
• C. $4 \times 10^{-3} V$
• D. $30 \times 10^{2} V$

Answer 1

Answer: (B)

$|e|=L \frac{d I}{d t}$
$|e|=6 \times 10^{-3}\left[\frac{I_{2}-I_{1}}{t_{2}-t_{1}}\right]$
$|e|=6 \times 10^{-3}\left[\frac{1}{40-20}\right]$
$e=3 \times 10^{-4} V .$