question_answer

The coereivity of a small bar magnet is \[{{\left( \frac{x}{a} \right)}^{n}}+{{\left( \frac{y}{b} \right)}^{n}}=2\] A/m. It is inserted inside a solenoid of 500 turns and length 1 m to demagnetize it. The amount of current to be passed through the solenoid will be

A) 2.5 A                     

B) 5 A    

C) 8 A                         

D) 10 A