Question

A rod of ferromegnetic materical with dimensions `10cmxx0.5cmxx2cm` is placed in a magnetising field of intensity `2xx10^(5)A//m`. The magnetic moment produced due it is `6` `amop-m^(2)`. The value of magnetic induction will be------`10^(-2)T`.
A. 0.358T
B. 0.54T
C. 6.28T
D. 2.519T

Answer 1

Correct Answer - B
`"Here", V=10xx0.5xx0.2cm^(3)=10^(-6)m^(3)`
`H=0.5xx10^(4)Am^(-1)=5xx10^(3)Am^(-1)`
`M=5Am^(-2), B=?`
`I=(M)/(A)=(5)/(10^(-6))=5xx10^(6)Am^(-1)`
`B=mu_(0)(H+I)`
`B=mu_(0)(H+I)`
`=4pixx10^(-7)(5xx10^(3)+5xx10^(6))`
`=4pixx10^(-7)xx5xx10^(6)(10^(-3)+1)=6.28T`