MHT CET · Physics · Electromagnetic Induction
If a current flowing in a coil is reduced to half of its initial value, the relation between the new energy \(\left(\mathrm{E}_2\right)\) and the original energy \(\left(E_1\right)\) stored in the coil will be
- A \(E_2=\frac{E_1}{4}\)
- B \(E_2=\frac{E_1}{2}\)
- C \(\mathrm{E}_2=\mathrm{E}_1\)
- D \(\mathrm{E}_2=\mathrm{4E}_1\)
Answer & Solution
Correct Answer
(A) \(E_2=\frac{E_1}{4}\)
Step-by-step Solution
Detailed explanation
\(\begin{aligned} & E_1=\frac{1}{2} L_1^2, \quad E_2=\frac{1}{2} L_2^2 \\ & \therefore \frac{E_2}{E_1}=\left(\frac{I_2}{I_1}\right)^2=\left(\frac{1}{2}\right)^2=\frac{1}{4} \\ & \therefore E_2=\frac{E_1}{4}\end{aligned}\)
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