Magnetism Question 93
Question: A magnet of magnetic moment M oscillating freely in earth’s horizontal magnetic field makes n oscillations per minute. If the magnetic moment is quadrupled and the earth’s field is doubled, the number of oscillations made per minute would be
[MP PET 1991]
Options:
A) $ \frac{n}{2\sqrt{2}} $
B) $ \frac{n}{\sqrt{2}} $
C) $ 2\sqrt{2}n $
D) $ \sqrt{2}n $
Show Answer
Answer:
Correct Answer: C
Solution:
No. of oscillation per minute $ =\frac{1}{2\pi }\sqrt{\frac{MB _{H}}{I}} $
$ \Rightarrow n\propto \sqrt{MB _{H}} M\to 4\times B _{H}\to 2\times $ So $ \nu \to \sqrt{8}\ times\ i.e.\ {\nu }’=\sqrt{8}\nu =2\sqrt{2}n $
BETA
