Question:
The current in a coil changes from 50A to 10A in 0.1 second. The self-inductance of the coil is 20H. The induced e.m.f. in the coil is:
The current in a coil changes from 50A to 10A in 0.1 second. The self-inductance of the coil is 20H. The induced e.m.f. in the coil is:
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The induced e.m.f. is directly related to the rate of change of current. A faster change in current results in a larger induced voltage.
Updated On: Mar 1, 2025
800V
6000V
7000V
- 8000V
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The Correct Option is D
Solution and Explanation
Step 1: According to Faraday's law of electromagnetic induction, the induced electromotive force (e.m.f.) in a coil is given by: \[ \mathcal{E} = -L \frac{dI}{dt}. \] Step 2: Given the values \( L = 20H \), \( dI = 50A - 10A = 40A \), and \( dt = 0.1s \), we calculate: \[ \mathcal{E} = - (20) \times \left( \frac{40}{0.1} \right) = 8000V. \]
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