Question

A 50 cm horizontal straight wire is place in a uniform magnetic field of magnetic field strength 0.5 T which is directed into the page Determine the magnitude and direction of the current to enable the wire remain float in equilibrium. Given the mass of the wire is 2 g.

Answer 1

$F_1=F_2,$

$IBl=mg,$

$I=\frac{mg}{Bl}=80~mA.$