Question

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

• A. $1200A/m$
• B. $2600A/m$
• C. $5200A/jm$
• D. $285A/m$

Answer 1

The correct option is B $2600A/m$

Coercivity $=H=\frac{B}{{\mu }_0}$
$ni=\frac{N}{\ell }i=\frac{100}{0.2}\times 5.2$
$=2600A/m$