Diamagnetism — Prelims Strategy

Prelims Strategy

To tackle NEET questions on diamagnetism effectively, focus on conceptual clarity and precise recall of properties. Firstly, understand that diamagnetism is universal and *induced*, arising from Lenz's Law, leading to opposition.

Memorize the key properties: weak repulsion, negative and small magnetic susceptibility ($chi < 0$), relative permeability slightly less than 1 ($mu_r < 1$), and crucial temperature independence. Practice identifying common diamagnetic examples like water, copper, and bismuth.

For numerical problems, these are usually straightforward applications of $mu_r = 1 + chi$. Pay close attention to the sign of susceptibility. When comparing with paramagnetism, remember diamagnetism is about *repulsion* and *temperature independence*, while paramagnetism is about *attraction* and *temperature dependence* (Curie's Law).

Trap options often involve confusing these properties or misidentifying materials. Always read the question carefully to determine if it asks for a correct or incorrect statement, or to identify a specific type of material.