Question

Magnetic field is measured in SI units of a tesla (T), and a current through a wire generates a field around the wire. The largest fields that we can make with most normal conducting materials carrying current are limited by the resistance of the wire and are around 1 tesla. For comparison, Earth's magnetic field is roughly 50 micro tesla You may have heard of a field unit called a gauss. It takes 10,000 G to make 1 T. What would be the maximum force on a wire 0.1 m long carrying a current of 80 A in a uniform magnetic field of 1 T? 8 N when the wire is perpendicular to the field

80 N when the wire is perpendicular to the field
8 N when the wire is parallel to the field
80 N when the wire is parallel to the field

Answer 1

The answer is 8 N

Step-by-step explanation:

The Lorentz force for a current carrying wire is

f = I * L x B

So, for magnetic forces to manifest the current must not be parallel to the magnetic field. So the cases where the wire is parallel to the field would result in a force of zero applied on the wires by the magnetic field because the cross product becomes zero.

For the perpendicular cases:

f = I * L * B

f = 80 * 0.1 * 1 = 8 N