Magnetism Question 293
Question: A bar magnet has coercivity $ 4\times 10^{5},A{{m}^{-1}} $ . It is desired to demagnetise it by inserting it inside a solenoid 12 cm long and having 60 turns. The current that should be sent through the solenoid is
Options:
A) 2 A
B) 4 A
C) 6 A
D) 8 A
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ n=\frac{N}{l}=\frac{60}{0.12}=500,,,turn,,,metr{{e}^{-1}} $
$ \Rightarrow ,,,i=\frac{H}{n}=\frac{4\times 10^{3}}{500}=8A $
BETA
