Magnetic Effects Of Current Question 177
Question: A small coil of N turns has an effective area A and carries a current I. It is suspended in a horizontal magnetic field $ \overrightarrow{B} $ such that its plane is perpendicular to $ \overrightarrow{B} $ . The work done in rotating it by $ 180{}^\circ $ about the vertical axis is [MP PMT 1994]
Options:
A) NAIB
B) 2NAIB
C) $ 2\pi NAIB $
D) $ 4\pi NAIB $
Show Answer
Answer:
Correct Answer: B
Solution:
$ W=MB( \cos {\theta_{1}}-\cos {\theta_{2}} ) $ $ =(NiA)\ B(\cos 0{}^\circ -\cos 180{}^\circ )=2NAIB $
BETA
