Physics · Class 12 · Chapter 6
Electromagnetic Induction
10 lessons 73 min 2 simulations
This chapter answers the question the last two left open: if currents make magnetic fields, can magnetic fields make currents? Faraday and Henry showed that they can, but only when the magnetic flux through a circuit changes. The chapter defines flux, states Faraday's law and Lenz's law, derives motional emf from both flux change and the Lorentz force, introduces mutual and self-inductance with the energy an inductor stores, and ends with the ac generator.
What the exam asks
NEET sets numericals on ε = −N dΦ/dt with the flux changed by B, area or angle; on motional emf Blv and the rotating-rod ½BωR²; on L and M of solenoids, ε = −L dI/dt and energy ½LI²; and on the generator's peak emf NBAω. Direction questions use Lenz's law. Marks are lost on cos θ in the flux, on forgetting N, on using the full length instead of ½ for a rotating rod, and on thinking a steady strong field induces an emf.
Lessons
10 lessons · 73 min
1The experiments of Faraday and HenryNCERT §6.1, §6.26 min2Magnetic fluxNCERT §6.35 min3Faraday's law of inductionNCERT §6.46 min4Lenz's law and conservation of energyNCERT §6.56 min5Motional emfNCERT §6.69 min 1 sim6Rotating rods and wheelsNCERT §6.65 min7Mutual inductanceNCERT §6.7, §6.7.16 min8Self-inductance and magnetic energyNCERT §6.7.26 min9AC generatorNCERT §6.89 min 1 sim10Chapter reviewMust-know facts, traps and formulas15 min