Question:
A paramagnetic sample shows a net magnetisation of 6 A/m when it is placed in an external magnetic field of 0.4 T at a temperature of 4 K. When the sample is placed in an external magnetic field of 0.3 T at a temperature of 24 K, then the magnetisation will be:
A paramagnetic sample shows a net magnetisation of 6 A/m when it is placed in an external magnetic field of 0.4 T at a temperature of 4 K. When the sample is placed in an external magnetic field of 0.3 T at a temperature of 24 K, then the magnetisation will be:
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Use Curie's law for a paramagnetic substance: \(M \propto B/T\).
Updated On: Nov 5, 2026
- 4 A/m
- 1 A/m
- 0.75 A/m
- 2.25 A/m
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The Correct Option is C
Solution and Explanation
By Curie's law, \(M = C\,\dfrac{B}{T}\).
From the first case: \(6 = C\times\dfrac{0.4}{4}\), so \(C = 60\) (in SI units A K T-1 m-1).
For the second case: \(M' = 60\times\dfrac{0.3}{24} = 0.75\) A/m.
Answer: (3) 0.75 A/m
From the first case: \(6 = C\times\dfrac{0.4}{4}\), so \(C = 60\) (in SI units A K T-1 m-1).
For the second case: \(M' = 60\times\dfrac{0.3}{24} = 0.75\) A/m.
Answer: (3) 0.75 A/m
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