JEE Main 12 Jan 2019 Evening Question 23

Question: A paramagnetic material has $ 10^{28}atoms/m^{3} $ . Its magnetic susceptibility at temperature 350 K is $ 2.8\times {10^{-4}}. $ Its susceptibility at 300 K is

[JEE Main Online Paper Held On 12-Jan-2019 Evening]

Options:

A) $ 3.267\times {10^{-4}} $

B) $ 3.672\times {10^{-4}} $

C) $ 2.672\times {10^{-4}} $

D) $ 3.726\times {10^{-4}} $

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Answer:

Correct Answer: A

Solution:

  • For a paramagnetic material, $ \chi \propto \frac{1}{T} $
    $ \Rightarrow $ $ {\chi_2}={\chi_1}\frac{T _1}{T _2}=2.8\times {10^{-4}}\times \frac{350}{300}=3.267\times {10^{-4}} $