Question

Which graph shows the variation of magnetic susceptibility (\( \chi \)) with magnetising field (\( H \)) for a paramagnetic substance?

• (A)
• (C)
• (B)
• (D)

Hint:

In magnetic susceptibility curves, paramagnetic substances show an increase in susceptibility with an increasing magnetic field, reaching saturation. This is best shown by graph (B).

Answer 1

The Correct Option is C

Step 1: Understanding the behavior of magnetic susceptibility.
Magnetic susceptibility (\( \chi \)) for a paramagnetic substance typically increases as the magnetic field (\( H \)) is applied and reaches a saturation value. At higher field strengths, the susceptibility tends to level off, showing a near-constant behavior.
Step 2: Analyzing the options.
(A) Graph (A): This graph shows a decreasing magnetic susceptibility as the magnetic field increases, which is incorrect for a paramagnetic substance.
(B) Graph (B): Correct — This graph shows the expected behavior of a paramagnetic substance where the susceptibility increases and then levels off at higher magnetic fields.
(C) Graph (C): This graph shows a saturated behavior but at an inappropriate initial stage. It does not represent the typical trend for paramagnetic substances.
(D) Graph (D): This graph shows an oscillating trend, which is incorrect for paramagnetic substances.
Step 3: Conclusion.
The correct answer is (B), as it correctly depicts the variation of magnetic susceptibility with the applied magnetic field for a paramagnetic substance.