Question

8. Magnetic potential energy of a needle
minimum when the angle between the
magnetic moment and magnetic field i
(a) 90°
(b) 30°
(c) 60°
(d) 0°​

Answer 1

Answer:

When angle is 90 b/w the magnetic field and magnetic moment, magnetic potential energy of a needle is minimum.

Answer 2

Magnetic potential energy of a needle  minimum when the angle between the  magnetic moment and magnetic field is 90 degrees.

Explanation:

The magnetic potential energy of a needle in magnetic field is given by the formula as follows :

$U=-\mu {\cdot} B$

or

$U=-\mu B\ cos\theta$

When $\theta=90^{\circ}$, the value of $cos(90)$ is equal to 0 i.e. the needle posses minimum potential energy. So, the correct option is (a) i.e. 90 degrees.

Learn more,

Magnetic potential energy

https://brainly.in/question/14117783