The magnetization of a bar magnet of length 5 cm,cross-sectional area `2 cm^(2)` and magnetic moment 1 `Am^(2)` is

Options

A. `1 xx10^(5) A/m`
B. `2 xx 10^(5) A/m`
C. `3 xx10^(5) A/m`
D. `4 xx 10^(5) A/m`

Answer

A

Explanation

The magnetic field inside the toroid in the absence of tungston=`B_(0)=mu_(0)H`
when filled with tungston,B=`mu_(0)(1+x)H`
The increse in the field =`B-B_(0)`
=`mu_(0)xH`
The percent increase in the magnetic field,
`(B-B_(0))/(B_(0))xx100`
`(mu_(0)xHxx100)/(mu_(0)H)=x xx 100`
`=6.8xx10^(-3)`