For a magnetising field of intensity `2xx10^3Am^-1`, aluminium at `280K` acquires intesity of magnetisation of `4*8xx10^-2Am^-1`. Find the susceptibility of aluminium at `280K`. If the temperature of the metal is raised to `320K`, what will be its susceptibility and intensity of magnetisation?

Answer

`2*4xx10^-5`; `2*1xx10^-5`, `4*2xx10^-2Am^-1`

Explanation

Here, `H=2xx10^3Am^-1`, `T=280K`.
`I=4*8xx10^-2Am^-1`
`chi_m=I/H=(4*8xx10^-2)/(2xx10^3)=2*4xx10^-5`
`T^'=320K, chi_m^'=?`
According to Curie's law, `chi_m^'/chi_m=T/T^'`
`:. chi_m^'=T/T^'xxchi_m=(280)/(320)xx2*4xx10^-5`
As `chi_m^'=I^'/H`
`:. I^'=chi_m^'H=2*1xx10^-5xx2xx10^3`
`=4*2xx10^-2Am^-1`