JEE Main201912 Jan 2019Evening ShiftPhysicsMagnetic Properties of MatterActual
A paramagnetic material has 10 28 atoms m - 3 . Its magnetic susceptibility at temperature 350 K is 2.8 × 10 - 4 . Its susceptibility at 300 K is
Options
- A3.726 x 10 - 4
- B2.672 x 10 - 4
- C3.267 x 10 - 4
- D3.672 x 10 - 4
Correct answer
C. 3.267 x 10 - 4
Step-by-step solution
From Curie's law, the magnetic susceptibility is inversely proportional to the temperature, i.e., χ ∝ 1 T Hence, the ratio of magnetic susceptibility at different temperature T 1 = 350   K and T 2 = 300   K . χ 2 χ 1 = T 1 T 2 χ 2 = χ 1 × T 1 T 2 = 2 . 8 × 10 - 4 × 350 300 χ 2 = 3 . 267 × 10 - 4 .