Question

A conductor of linear mass density 0.2 g m1 suspended by two flexible wire as shown in figure. Suppose the tension in the supporting wires is zero when it is kept inside the magnetic field of I T whose direction is into the page. Compute the current inside the conductor and also the direction for the current. Assume g = 10 m s^-2.

Answer 1

Downward force, F = mg

Linear mass density, `m/l` = 0.2 gm^-1

`m/l` = 0.2 x 10^-3 kg m^-1

m = (0.2 x 10^-3 x l) kg m^-1

F = (0.2 x 10^-3 x l x 10) N

Upward magnetic force acting on the wire

F = BIl

0.2 x 10^-3 x l x 10 = 1 x I x l

I = 2 x 10^-3

I = 2 m A