CBSE 12 Physics · U4
Electromagnetic Induction and Alternating Currents
CBSE Class 12 Physics Unit IV: Faraday's law, Lenz's law, induced emf and current, motional emf, eddy currents, self and mutual induction, AC peak and RMS values, reactance, impedance, LCR resonance, AC power, generators, and transformers.
Test yourself
A focused, distraction-free run through 26 multiple-choice questions. Hints if you need them; your score at the end.
Difficulty guide
The label describes the problem, not your ability.
1/5 - Foundational
Warm-up setup; checks one basic idea.
2/5 - Routine exam skill
Normal syllabus skill; usually one main rule or interpretation.
3/5 - Standard multi-step
Exam-style problem with multiple steps or a common trap.
4/5 - Hard exam skill
High-end exam problem; combines methods carefully.
5/5 - Challenge
Stretch problem beyond normal exam pressure.
Topic 4.1
Faraday's Law and Magnetic Flux
Magnetic flux, Faraday's law, induced emf and current, and interpreting flux-time graphs.
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Topic 4.2
Lenz's Law, Motional Emf, and Eddy Currents
Direction of induced current, motional emf in conductors, energy opposition, and eddy-current effects.
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Topic 4.3
Self and Mutual Induction
Self-induced emf, mutual induction, flux linkage, inductance, and energy stored in an inductor.
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Topic 4.4
Alternating Current, Reactance, and Impedance
Peak and RMS values, frequency, capacitive and inductive reactance, impedance and phase in AC circuits.
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Topic 4.5
LCR Resonance, AC Power, Generator, and Transformer
Series LCR resonance, power factor, wattless current, AC generator, transformer ratios and power transfer.
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