Magnetic Effects Of Current Question 229
Question: Current i is carried in a wire of length L. If the wire is turned into a circular coil, the maximum magnitude of torque in a given magnetic field B will be [Pb. PET 2004]
Options:
A) $ \frac{LiB^{2}}{2} $
B) $ \frac{Li^{2}B}{2} $
C) $ \frac{L^{2}iB}{4\pi } $
D) $ \frac{Li^{2}B}{4\pi } $
Show Answer
Answer:
Correct Answer: C
Solution:
$ {\tau_{\max }}=NiAB=1\times i\times (\pi r^{2})\times B $ $ ( 2\pi r=L,\Rightarrow r=\frac{L}{2\pi } ) $ $ {\tau_{\max }}=\pi i{{( \frac{L}{2\pi } )}^{2}}B=\frac{L^{2}iB}{4\pi } $
BETA
