Q1
An AC generator converts:
📝 SolutionAn AC generator works on electromagnetic induction, converting mechanical energy (used to rotate a coil in a magnetic field) into electrical energy.
Q2
In an AC generator, the emf induced is maximum when the plane of the coil is:
📝 SolutionEmf $\varepsilon = NBA\omega\sin(\omega t)$ is maximum when $\sin(\omega t) = 1$, which occurs when the coil plane is parallel to $B$ (flux through it is momentarily zero but rate of change is greatest).
Q3
Assertion (A): A changing magnetic flux through a coil induces an emf even if the coil is not connected to any battery.
Reason (R): According to Faraday's law, emf is induced whenever the magnetic flux linked with a circuit changes with time.
Choose the correct option:
Reason (R): According to Faraday's law, emf is induced whenever the magnetic flux linked with a circuit changes with time.
Choose the correct option:
📝 SolutionFaraday's law shows emf arises purely from a changing flux, regardless of any external source like a battery; the coil itself becomes a source of emf. R correctly explains A.
Q4
Assertion (A): The induced current always flows in a direction that opposes the change producing it.
Reason (R): This behaviour is a direct consequence of the law of conservation of energy.
Choose the correct option:
Reason (R): This behaviour is a direct consequence of the law of conservation of energy.
Choose the correct option:
📝 SolutionLenz's law (A) ensures that work is required to change the flux; if the induced current aided the change instead, energy could be created from nothing, violating conservation of energy. R correctly explains A.
Q5
Two coils are wound on the same iron core to maximise their mutual inductance. This principle is used in a:
📝 SolutionA transformer uses two coils (primary and secondary) wound on a common iron core to achieve strong magnetic coupling, allowing efficient transfer of electrical energy via mutual induction.
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Class 12 · Physics
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