Magnetism Question 171
Question: Two short magnets with their axes horizontal and perpendicular to the magnetic meridian are placed with their centres 40 cm east and 50 cm west of magnetic needle. If the needle remains undeflected, the ratio of their magnetic moments $ M _{1}:M _{2} $ is
[MP PET 1990]
Options:
A) 4 : 5
B) 16 : 25
C) 64 : 125
D) $ 2:\sqrt{5} $
Show Answer
Answer:
Correct Answer: C
Solution:
For null deflection $ \frac{M _{1}}{M _{2}}={{( \frac{d _{1}}{d _{2}} )}^{3}}={{( \frac{40}{50} )}^{3}}=\frac{64}{125} $
BETA
