Magnetism Question 270
Question: Two short magnets with their axes horizontal and perpendicular to the magnetic maridian 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
Options:
A) 4 : 5
B) 16 : 25
C) 64 : 125
D) $ 2:\sqrt{5} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] For null deflection $ \frac{M _{1}}{M _{2}}={{( \frac{d _{1}}{d _{2}} )}^{3}}={{( \frac{40}{50} )}^{3}}=\frac{64}{125} $
BETA
