Question

The magnetic susceptibility $\chi$ for superconductors is ______.

• A. Zero
• B. 1
• C. 0.1
• D. -1

Hint:

Perfect diamagnetism ($\chi = -1$) is what allows magnets to "levitate" over a superconductor—the material creates an equal and opposite magnetic field to push the magnet away.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Superconductors exhibit the Meissner Effect, where they expel all magnetic magnetic flux from their interior when cooled below a critical temperature.
Step 2: Detailed Explanation:
For a material, $B = \mu_0(H + I)$. Inside a superconductor, $B = 0$, so $I = -H$. Magnetic susceptibility is defined as $\chi = I/H$. $$\chi = \frac{-H}{H} = -1$$ This indicates that superconductors are perfectly diamagnetic.
Step 3: Final Answer:
The correct option is (d).