Question

B is the magnetic flux density and \( T_c \) is the critical temperature. The Meissner effect is represented by:

• A. \( B = 0 \) at \( T \leq T_c \)
• B. \( B = 0 \) at \( T>T_c \)
• C. \( B \neq 0 \) at \( T \leq T_c \)
• D. \( \nabla B = 0 \) at \( T = T_c \)

Hint:

The Meissner effect occurs in superconductors below their critical temperature, where the material expels magnetic fields. Remember that \( B = 0 \) for \( T \leq T_c \).

Answer 1

The Correct Option is A

The Meissner effect is a fundamental property of superconductors, where the material expels magnetic fields when it transitions into the superconducting state. This effect occurs below a critical temperature \( T_c \), where the superconducting material completely excludes any magnetic flux from its interior.
When a material is in the superconducting state, the magnetic flux density \( B \) becomes zero inside the material. This means that the magnetic field is expelled from the material when \( T \leq T_c \).
Therefore, the correct representation of the Meissner effect is:
\[ B = 0 {at} T \leq T_c \] This means that the magnetic field is expelled from the material below the critical temperature \( T_c \). The correct option is (A).