Question

A paramagnetic sample shows a net magnetisation of 8 Am^–1 when placed in an external magnetic field of 0.6 T at a temperature of 4 K. When the same sample is placed in an external magnetic field of 0.2 T at a temperature of 16 K, the magnetisation will be ______.

विकल्प

• `32/3` Am^–1

• `2/3` Am^–1

• 6 Am^–1

• 2.4 Am^–1

Answer 1

A paramagnetic sample shows a net magnetisation of 8 Am^–1 when placed in an external magnetic field of 0.6 T at a temperature of 4 K. When the same sample is placed in an external magnetic field of 0.2 T at a temperature of 16 K, the magnetisation will be `underline(2/3 Am^(–1))`.

Explanation:

i.e., `I("magnetization")  oo (B("magnetic field induction"))/(t("temperature in kelvin"))`

⇒ `I_2/I_1 = B_2/B_1 xx t_1/t_2`

Let us suppose, here `I_1 = 8  Am^(-1)`

`B_1 = 0.6  T, t_1 = 4  K`

`B_2 = 0.2  T, t_2 = 16  K`

`I_2` = ?

⇒ `0.2/0.6 xx 4/16 = I_2/8`

⇒ `I_2 = 8 xx 1/12 = 2/3  Am^(-1)`