Magnetism Question 211
Question: The work done in rotating a magnet of magnetic moment 2 A-m2 in a magnetic field of 5 ´ 10?3 T from the direction along the magnetic field to opposite direction to the magnetic field, is
[MP PET 2003]
Options:
A) Zero
B) 2 ´ 10?2 J
C) 10?2 J
D) 10 J
Show Answer
Answer:
Correct Answer: B
Solution:
$ W=MB(1-\cos \theta ); $ where $ \theta =180^{o} $
$ \Rightarrow W=2MB\Rightarrow W=2\times 2\times 5\times {{10}^{-3}}=2\times {{10}^{-2}}J $
BETA
