Forces Between Electricity & Magnets
Physics: Cambridge International GCSE Supplement, topic 4.11.3
Forces Between Electricity and Magnets
When an e.m.f is induced in a wire, it creates a force acting in the opposite direction to the action that induced the e.m.f. This is due the motor effect (covered later).
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Moving downwards
- If a wire moves downwards into a horseshoe magnet:
- An e.m.f is induced in the wire and an electric current flows through the wire.
- A force will push the wire upwards, opposing the downwards movement of the wire that induced the e.m.f.
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Moving upwards
- If the wire was moving upwards to create the e.m.f, then the force on the wire due to the induced e.m.f would push it downwards.
Test yourself on Forces Between Electricity & Magnets
Which of these statements are features of the motor effect?
In which direction does a force induced by the motor effect run?
"When an e.m.f is induced in a wire, it creates a force acting in the opposite direction to the action that induced the e.m.f." Which effect causes this?