Find the percent increase in the magnetic field `B` when the space within a current- carrying toroid is filled with aluminium. The susceptibility of aluminium is `2.1 xx 10^(-5)`.

Options

A. `3.1xx10^(-3)`
B. `1.1xx10^(-3)`
C. `2.1xx10^(-3)`
D. `2.1xx10^(-5)`

Answer

C

Explanation

Ibn the absence of `A1,B_(0)=mu_(0)H` and in the presence of `A1`
`B=muH=mu_(0)(1+chi)H`
`%`age increase
`=(B-B_(0))/(B_(0))xx100=(mu_(0)chiH)/(muH)xx100`
`=chixx100=(2.1xx10^(-5))100=2.1xx10^(-3)`