Magnetism Question 268
Question: The time period of oscillation of a bar magnet suspended horizontally along the magnetic meridian is $ T _{0} $ . If this magnet is replaced by another magnet of the same size and pole strength but with double the mass, the new time period will be
Options:
A) $ \frac{T _{0}}{2} $
B) $ \frac{T _{0}}{\sqrt{2}} $
C) $ \sqrt{2}T _{0} $
D) $ 2T _{0} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ I _{1}=\frac{m{{\ell }^{2}}}{12} $ and $ I _{2}=\frac{(2m){{\ell }^{2}}}{12}=2I _{1} $ . Now, $ \frac{T _{1}}{T _{2}}=\sqrt{\frac{I _{1}}{I _{2}}} $ or $ \frac{T _{0}}{T _{2}}=\sqrt{\frac{1}{2}} $
$ \
Therefore ,,,,T _{2}=\sqrt{2},T _{0} $
BETA
