Question

Current in a coil increases from 0 to 1 ampere in 0.1 second. If self inductance of the coil is 5 millihenry, magnitude of induced emf is

• A. $5V$
• B. $5\times {10}^{-3}V$
• C. $0.5V$
• D. $5\times {10}^{-2}V$

Answer 1

The correct option is D $5\times {10}^{-2}V$

$E=-L\frac{di}{dt}$
$=-5\times {10}^{-3}\times \frac{1-0}{0.1}=-5\times {10}^{-2}$
$E=5\times {10}^{-2}V$