A loop of 5 turns of wire is placed in uniform magnetic field of 0.5T, then area of loop shrinks at a constant rate of 10m²/s, the emf induced is:
Correct answer: B. 25V
- A. 2.5V
- B. 25V
- C. 250V
- D. 0.25V
Explanation
According to faraday's law of electromagnetic induction, whenever there is change in magnetic flux, in this particular case there's change in area of loop, an emf e is induced in the coil. Mathematically e = -NdⲪ/dt -sign is due to lenz's law Solution of the problem is shown in figure below:
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About Faraday's Law
Faraday's law states that an induced electromotive force equals the rate of change of magnetic flux linkage through a circuit. Questions cover changing field, area, angle or motion, the negative sign associated with Lenz's law, and the distinction between induced emf and the current that may flow in a closed circuit.
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