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Mistake Master · AP Physics C: E&M · Unit 13 · Step-Through Animation

The Push That Pushes Back

You'll learnwhy a rod sliding along rails acts like a battery, and why the field always pushes back on it.

A metal rod slides along two rails in a magnetic field, and a bulb lights with no battery anywhere. Keeping it lit costs you a push, and the field tells you exactly how hard. Twelve short steps; press Next for each one.

12 STEPS · 6 QUICK CHECKS · THE ROD IS THE BATTERY · THE FIELD PUSHES BACK · v2

the rod is the battery · the field pushes back on it
Before you start
What you're looking at
A metal rod that slides along two rails in a magnetic field, with a bulb wired across the far end. No battery anywhere.
The question
What lights the bulb, and what does the rod feel while it is lit?
Step 1 / 12