Question 97: Magnetism and Matter

Question

A bar magnet is demagnetized by inserting it inside a solenoid of length 0.2 m, 100 turns, and carrying a current of 5.2 A. The corecivity of the bar magnet is :

Accepted Answer

Coercivity, H = $${B \over {{\mu _0}}}$$
Inside solenoid the magnetic field,
B  = $$\mu $$
0
ni
$$ 	herefore $$   H = $${{{\mu _0}ni} \over {{\mu _0}}}$$
=  ni
= $${N \over \ell } 	imes i$$
=  $${{100} \over {0.2}} 	imes 5.2$$
= 2600 A/m

Answer

285 A/m

Answer

2600 A/m

Answer

520 A/m

Answer

1200 A/m

Magnetism and Matter

A bar magnet is demagnetized by inserting it inside a solenoid of length 0.2 m, 100 turns, and carrying a current of 5.2 A. The corecivity of the bar magnet is :

Choose the correct answer: