Question

A straight wire of mass 200gm and length 1.5m carries a current of 2A.It is suspended horizontally in mid air by a uniform magnetic field B.Find the magnitude of B?

Answer 1

Mass of wire (m) = 200 grams or 0.2 kg

length (L) = 1.5 m

Current (I) = 2 A

Acceleration due to gravity (g) = 9.8 m/s^2

The weight of the wire will be balanced by the magnetic force acting in the opposite direction.

Let the magnetic field be B.

mg = ILB

B = 0.653 T

The value of uniform magnetic field is 0.653 T.