A paramagnetic sample shows a net magnetisation of `8Am^-1` when placed in an external magnetic field of `0*6T` at a temperature of `4K`. When the same sample is placed in an external magnetic field of `0*2T` at a temperature of `16K`, the magnetisation will be

Options

A. `(32)/(3)Am^(-1)`
B. `(2)/(3)Am^(-1)`
C. `6 Am^(-1)`
D. `2.4 Am^(-1)`

Answer

B

Explanation

As curie law explains, we can deduce a formula for the relation between magnetic field induction, tempreature and magnetisation.
`i.e.,`
`I("magnetisation")oo(B("magnetic field induction"))/(t("tempreture in kelvin"))`
`rArr (I_(2))/(I_(1))=(B_(2))/(B_(1))xx(t_(1))/(t_(2))`
Let us suppose, here `I_(1)=8 Am^(_1)B_(1)=0.6T, t_(1)=4K`
`B_(2)=0.2T,t_(2)=16K`
`rArr (0.2)/(0.6)xx(4)/(16)=(I_(2))/(8)`
`rArr`
`I_(2)=8xx(1)/(12)=(2)/(3)Am^(-1)`