Question

6-Torque on a coil. A circular loop of wire has a diameter of 20.0 cm and contains 10 loops. The current
in each loop is 3.00 A, and the coil is placed in a 2.00-T external magnetic field. Determine the maximum
and minimum
torque exerted on the coil by the field.

Answer 1

Let the maximum torque is .

Let the minimum torque is .

The number of loops N=20.

Current in each loop I=3.00 A

Let the area of each loop is A.

  

Magnetic field B=2.00 T.

We know Torque

Here is the angle between magnetic field strength and the direction of the area of the loop.

Now the torque is maximum when

.

  

     

Now the torque is minimum if

.

  

The maximum torque is 3.77 N.m .

The minimum torque is 0 N,m .