The magnetic susceptibility of a paramagnetic substance at `- 173 .^(@)C` is `1.5 xx 10^(-2)` then its value at

Options

A. `7.5xx10^(-1)`
B. `7.5xx10^(-2)`
C. `7.5xx10^(-3)`
D. `7.5xx10^(-4)`

Answer

C

Explanation

In paramagnetic substance, the magnetic susceptibility
`chi=C/T=(chi_(1))/(chi_(2))=(T_(2))/(T_(1))`
Then `chi_(2)=chi_(1)(T_(1))/(T_(2))`
Here `ch_(1)=1.5xx10^(-2)`
`T_(1)=273-173=100K`
`T_(2)=273-73=200K`
`:.chi_(2)=1.5xx10^(-2)xx100/200`
`=7.5xx10^(-3)`