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MHT CET · Physics · Electromagnetic Induction

An average induced emf of \(0.5 \mathrm{~V}\) appears in a coil when the current in it is changed from \(10 \mathrm{~A}\) in one direction to \(10 \mathrm{~A}\) in opposite direction in 0.8 second. The self-inductance of the coil is

  1. A 50 mH
  2. B 20 mH
  3. C 25 mH
  4. D 40 mH
Verified Solution

Answer & Solution

Correct Answer

(A) 50 mH

Step-by-step Solution

Detailed explanation

\(e=L \frac{d I}{d t}=L\left(\frac{20}{0.5}\right)=40 L\) and \(e=0.5 \mathrm{~V}\)
\(\therefore L=\frac{2}{40} \mathrm{H}=0.05 \mathrm{H}=50 \mathrm{mH}\)