An induced emf is produced when a magnet is plunged into a coil. The magnitude of the induced emf is independent of
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → the resistivity of the wire of the coil
The induced emf in a coil is given by Faraday's law:
$\mathcal{E} = -N \frac{d\Phi}{dt}$, where $N$ = number of turns, $\Phi$ = magnetic flux
Factors affecting emf:
→ Strength of the magnet → affects flux → emf changes
→ Speed of magnet → affects rate of change of flux → emf changes
→ Number of turns → directly proportional → emf changes
→ Resistivity of the wire → does not affect emf; it affects current, not emf
∴ Magnitude of induced emf is independent of the resistivity of the wire of the coil