Class 12 Physics: how to help with Electromagnetic Induction when you do not know the physics

Can you help with Class 12 Physics if the last time you met Faraday was in school? Yes. You just need to change the job. Your child doesn't need a second teacher at home. They need someone who'll sit still and listen while they explain, because explaining is one of the quickest ways to find out what's still fuzzy. Electromagnetic Induction makes a good example.

The chapter in four lines

• Flux and Faraday's law. Magnetic flux counts how much field passes through a surface, and it depends on the field, the area and the tilt. When the flux changes, an emf appears. A steady flux doesn't induce one.
• Lenz's law. The induced current flows so that its own field opposes the change in flux. That's energy conservation at work.
• Motional emf. A conductor moving through a magnetic field develops an emf between its ends.
• Inductance and the AC generator. A coil resists changes in the current through it, and a coil spun in a field produces an alternating emf.

You can't follow every detail, and that's fine. One question carries you a long way: "What's changing, and what's pushing back?"

What to ask

Here are four ways in. Pick whichever suits the evening.

Play a Class 8 student. "Explain Faraday's law to me as if I'm in Class 8." If your child can do that in plain words, they know it. If they start reciting a formula, ask "and what does that mean?"

Ask about the cause. "What has to change for a current to appear?" The answer you're listening for is a change in flux. A magnet sitting still next to a coil does nothing.

Ask about the opposite case. "What happens when the magnet goes in, and what happens when it comes out?" Direction flips are where slips love to hide.

Ask for something from home. Where have they seen induction? A generator, a transformer, an induction cooktop, a tubelight choke. The chapter page mentions several of these. A child who can name one and say what's changing inside it has understood more than one who can only recite.

Three questions, no book

Let your child do the talking.

1. What exactly has to change for an emf to be induced in a loop?
2. A magnet's north pole moves towards a coil. What does Lenz's law say about the field of the induced current?
3. Why does a faster change give a bigger induced emf?

If the answers come out in their own words, that idea is secure. If one gets tangled, that's the one to revisit, and you can check it against the textbook together. You don't have to judge the answer. Nobody's being marked.

Your actual role

You're not the answer key. You're the audience, the timekeeper and the calm voice at 9 pm. Ten minutes of "explain it to me" most evenings does more than one long night of silent worry.

The chapter in small pieces

The chapter page splits it into four ideas, each with key words, formulas and a two-minute activity: Electromagnetic Induction, Class 12 Physics.

If you'd like to test the ideas afterwards

KRIGYAN has short quizzes and games for Class 12 Physics chapters like this one, and a parent view showing which ideas look strong and which need another go. We're a young product and still fixing things, so your feedback counts. It's free to try right now. Send us the class and chapter you're stuck on, and we'll let you know straight whether it's in yet.