Question
Question: A uniform horizontal magnetic field of 7.5 x 10-2 T is set up at an angle of 30° with the axis of an...
A uniform horizontal magnetic field of 7.5 x 10-2 T is set up at an angle of 30° with the axis of an solenoid and the magnetic moment associated with it is 1.28 J T-1. Then the torque on it is
A
4.8 x 10-2 N m
B
1.6x10-2N m
C
1.13 x 10-2 kg m
D
4.8 x 10-4 N m
Answer
4.8 x 10-2 N m
Explanation
Solution
: Torque, ,
Here, ,
∴τ=1.28×7.5×10−2sin30∘
=1.28×7.5×10−2×21
=0.64×7.5×10−2=4.8×10−2Nm