A coil of self-inductance 20 mH allows a variable current of I = 0.2 sin 100 t to pass through it. Calculate the maximum magnitude of emf induced in the coil.

Explanation

To solve the problem of finding the maximum magnitude of emf induced in a coil with a given self-inductance and a variable current, we can follow these steps:

### Step 1: Understand the given values
- Self-inductance (L) = 20 mH = 20 × 10^(-3) H
- Variable current (I) = 0.2 sin(100t) A

### Step 2: Write the formula for induced emf
The induced emf (ε) in a coil is given by Faraday's law of electromagnetic induction:
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