Difficulty: Easy
Correct Answer: Opposite to the applied field
Explanation:
Introduction / Context:
This question targets basic diamagnetism. In many materials with no permanent dipoles (closed electron shells), an applied magnetic field induces orbital currents that oppose the change in magnetic flux, creating an induced dipole moment.
Given Data / Assumptions:
Concept / Approach:
Lenz’s law and the classical Langevin viewpoint show that induced currents generate magnetic moments opposing the applied field. Quantum mechanically, Larmor precession leads to an induced magnetic moment antiparallel to the applied field. This universal, weak effect is diamagnetism, present in all materials but usually masked when paramagnetic or ferromagnetic effects exist.
Step-by-Step Solution:
Verification / Alternative check:
Magnetic susceptibility of diamagnets is small and negative, confirming antiparallel induced magnetization (M opposite to H).
Why Other Options Are Wrong:
Common Pitfalls:
Confusing induced diamagnetism with alignment of permanent moments; overlooking that most materials exhibit at least weak diamagnetism.
Final Answer:
Opposite to the applied field
Discussion & Comments