A sample of paramagnetic salt contains `2xx10^(24)` atomic dipoles, each of moment `1.5xx10^(-23)JT^-1`. The sample is placed under a homogeneous magnetic field of `0.64T` and cooled to a temperature of `4.2K`. The degree of magnetic saturation archieved is equal to `15%`. What is the total dipole moment of the sample for a mangetic field of `0.98T` and a temperature of `2.8K`. (Assume Curie's law).

Explanation

Initially , total dipole moment ` = 0.15 xx 1.5 xx 10^(-23) xx 2.0 xx 10^(24) = 4.5 JT^(-1)`
Use Curie. Law m `alpha` B/T to get the final diople moment
` = 4.5 xx (0.98// 0.84)xx (4.2 // 2.8) = 7.9 JT^(-1)`