A bar magnet is located next to a coil of wire that is fixed in position and connected to an ammeter , as shown above. There will be an induced electric current through the ammeter if the magnet is moving in which of the following ways?
|I.||Toward the coil with constant speed|
|II.||Toward the coil with increasing speed|
|III.||Away from the coil with constant speed|
|IV.||Away from the coil with increasing speed|
Select an Answer
or or or
The correct answer is all four motions. Since the magnetic field extending from the end of the bar magnet is non-uniform, any motion of the magnet will cause a change in the magnetic flux passing through the coil. This, in turn, causes an induced emf and thus a current in the coil.