KCET · Physics · Electromagnetic Induction
Current in a coil changes from \(4 \mathrm{~A}\) to zero in \(0.1 \mathrm{~s}\) and the emf induced is \(100 \mathrm{~V}\). The self inductance of the coil is
- A \(0.25 \mathrm{H}\)
- B \(0.4 \mathrm{H}\)
- C \(2.5 \mathrm{H}\)
- D \(4 \mathrm{H}\)
Answer & Solution
Correct Answer
(C) \(2.5 \mathrm{H}\)
Step-by-step Solution
Detailed explanation
Induced emf, \(e=\frac{-L d I}{d t}\)
\(\therefore 100 =\frac{-L[0-4]}{0.1} \)
\(\Rightarrow L =\frac{100 \times 0.1}{4} \)
\(=2.5 \mathrm{H}\)
\(\therefore 100 =\frac{-L[0-4]}{0.1} \)
\(\Rightarrow L =\frac{100 \times 0.1}{4} \)
\(=2.5 \mathrm{H}\)
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