Question

To understand the origin of the torque on a current loop due to the magnetic forces on the current-carrying wires.

Answer 1

Answer:

The torque is  $\tau = B * m sin(\phi )$

Explanation:

Generally when current flow through a rectangular loop the magnetic dipole generated we can denote this as  $\vec m$

Here k is the length of the side of one side of the rectangular loop

Now when this loop is place in a magnetic field, the torque it experience is mathematically represented as

      $\vec \tau = \vec B \ X \ \vec m$

Here  X stands for cross - product

From the question we are told that the angle between the vector ( $\vec m$)perpendicular to the plane of the coil and magnetic field(B) as $\phi$

So

=>     $\tau = B * m sin(\phi )$