The susceptibility of magnesium at `300 K` is `1.2 xx 10^(-5)`. At what temperature will the susceptibility increase to `1.8 xx 10^(-5)`?

Explanation

Given : ` chi _( m _ 1) ` ( at 300 K ) = ` 1.2 xx 10 ^( - 5 ) , T _ 1 = 300 K`,
` chi_( m _ 2 ) = 1.8 xx 10 ^( - 5 ) `
According to Curie's law
` chi _( m ) prop ( 1 ) /(T) `
` therefore ( chi _ (m _ 1 )) /( chi _ ( m _ 2 ) ) = ( T _ 2 )/ ( T _ 1 ) `
` therefore ` The required temperature,
` T _ 2 = ( chi _ ( m _ 1 )) /( chi _ ( m _ 2)) xx T _ 1 `
` = ( 1.2 xx 10 ^( - 5 ) ) /( 1.8 xx 10 ^( - 5) ) xx 300 `
` = ( 2 ) /( 8) xx 300 = 200 ` K