Brainlag PlusThe force on a current in a magnetic field, Fleming's left-hand rule, F = BIl with the tesla, and why the coil of a motor keeps turning.
Two fields, one push
Put a wire carrying a current in the field of a magnet.
The wire's own field and the magnet's field interact, and the wire feels a force. That is the motor effect.
Fleming's left-hand rule. Hold your left thumb, first finger and second finger at right angles:
- First finger: Field (N to S)
- seCond finger: Current
- thuMb: Motion (the force)
Reverse the current or the field and the force reverses. Reverse both and it is back as before. A wire lying along the field lines feels no force.
The rest of this lesson and its 10 practice questions are in Plus.
Screen 1 of 4, free to read.
- 10 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards