Electromagnetism and the Motor Effect

Question 1

True or false? The strength of a magnetic field around a current-carrying wire increases as you move away from the wire.

Answer 1

False

The greater the distance from the wire, the weaker the magnetic field will be

Question 2

Why might a current-carrying wire move when placed between magnetic poles?

Answer 2

The magnetic field around the wire interacts with the magnetic field between the poles. This causes the magnet (or magnets) and the wire to exert a force on each other. This force can cause the wire to move.

Question 3

A 0.1m length of wire is in a magnetic field, at 90° to the field. It is carrying a current of 10 A and experiences a force of 0.02N. Calculate the magnetic flux density of the magnetic field using the formula F = B x I X l, where F = force, B = magnetic flux density, I = current, l = length of wire in the field

Answer 3

0.02 T
Rearrange F = B x I x l for B:
B = F / (I x l) = 0.02 / (10 x 0.1) = 0.02T