Magnetism Question 80
Question: Two magnets of same size and mass make respectively 10 and 15 oscillations per minute at certain place. The ratio of their magnetic moments is
[Bihar PET 1984; MP PET/PMT 1988; MP PET 1992]
Options:
A) 4 : 9
B) 9 : 4
C) 2 : 3
D) 3 : 2
Show Answer
Answer:
Correct Answer: A
Solution:
$ T=2\pi \sqrt{\frac{1}{MB _{H}}}\Rightarrow \frac{T _{1}}{T _{2}}=\sqrt{\frac{M _{2}}{M _{1}}} $
$ \Rightarrow \frac{M _{1}}{M _{2}}=\frac{T _{2}^{2}}{T _{1}^{2}}=\frac{{{( 60/15 )}^{2}}}{{{( 60/10 )}^{2}}}=\frac{4}{9} $
BETA
