Question

The force exerted on a current-carrying wire placed in a magnetic field is zero when the angle between the wire and the direction of magnetic field is :

(a) ${45}^o$ (a) ${60}^o$ (a) ${90}^o$ (d) ${180}^o$

Answer 1

(d) ${180}^o$

The force experienced by a current carrying conductor in a magnetic field = ilBsinA

where

i is the intensity of current current carried by the conductor
l is the length of the conductor
b is the strength of the magnetic field in which the conductor is placed
and

A is the angle between the conductor and direction of magnetic field

as maximum value of sinA is 0 and this happens when the angle is 180 degrees