Question

The potential energy of a bar magnet of magnetic moment 8 A m2 placed in a uniform magnetic field of 2 T
at an angle of 120° is equal to
(1) -16 J
(2) 16 J
(4) -8 J
(3) 8J​

Answer 1

Answer:

Correct option is

D

8J

Given: Magnetic moment = 8Am

2

Magnetic field = 2T

θ=120

∘

Solution: The potential energy of a bar magnet is given by,

U=−MBcosθ

U=−8×2×cos120

∘

As, cos120

∘

=−

2

1

On solving we get,

U=+8J

Hence, the correct option is (D).

Answer 2

Answer:

❣Answer❣

➡Option 4 ( -8j)