Question

a magnetic needle of magnetic moment 0.2A-m is placed in a region with uniform magnetic field 4T. the maximum torque experienced by the needle will be​

Answer 1

Given:

A magnetic needle of magnetic moment 0.2A-m is placed in a region with uniform magnetic field 4T.

To find:

Maximum Torque ?

Calculation:

The torque experienced by a magnetic needle in a magnetic field intensity is expressed as follows:

$\tau = MB \sin( \theta)$

• 'M' is magnetic moment, 'B' is Field Intensity and $\theta$ is the angle between the the magnetic moment vector and the field intensity vector.

• Now, max torque is when $\theta$ = 90° , because that's the max value for sine.

Putting the respective values:

$\implies\tau_{max} = MB \sin( {90}^{ \circ} )$

$\implies\tau_{max} = MB$

$\implies\tau_{max} = 0.2 \times 4$

$\implies\tau_{max} = 0.8 \: Nm$

So , max torque experienced is 0.8 Nm.