Magnetism Question 32
Question: In a vibration magnetometer, the time period of a bar magnet oscillating in horizontal component of earth’s magnetic field is 2 sec. When a magnet is brought near and parallel to it, the time period reduces to 1 sec. The ratio H/F of the horizontal component H and the field F due to magnet will be
[MP PMT 1990; Pb PET 2000]
Options:
A) $ 3 $
B) $ 1/3 $
C) $ \sqrt{3} $
D) $ 1/\sqrt{3} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ T\propto \frac{1}{\sqrt{H}}\Rightarrow \frac{T _{1}}{T _{2}}=\sqrt{\frac{H _{2}}{H _{1}}}\Rightarrow \ \frac{2}{1}=\sqrt{\frac{H+F}{H}}\Rightarrow F=3H $ or $ \frac{H}{F}=\frac{1}{3} $
BETA
