Compounds are categorized by their interaction with an external magnetic field. These categories are diamagnetic, paramagnetic, and ferromagnetic:
1. Diamagnetic substances: These materials exhibit weak repulsion from a magnetic field and lack unpaired electrons. All electrons in diamagnetic substances are paired, resulting in no net magnetic moment. Consequently, diamagnetic compounds are repelled by external magnetic fields. \( \text{NaCl} \) is an example of a diamagnetic substance.
2. Paramagnetic substances: These materials show weak attraction to a magnetic field, a property stemming from unpaired electrons that orient with the field. Their magnetic effect is less pronounced than that of ferromagnetic substances. \( \text{FeCl}_3 \) serves as an example of a paramagnetic substance, as the iron ion (\( Fe^{3+} \)) possesses unpaired electrons.
3. Ferromagnetic substances: These substances demonstrate strong attraction to magnetic fields, attributed to the coordinated alignment of unpaired electrons. This behavior is observed in materials such as iron, cobalt, and nickel.
Analyzing the provided options:
- \( \text{FeCl}_3 \) is paramagnetic and will be attracted to an external magnetic field due to unpaired electrons in iron.
- \( \text{FeSO}_4 \) is also paramagnetic, exhibiting attraction to the magnetic field because of unpaired electrons in \( Fe^{2+} \).
- \( \text{NaCl} \) is diamagnetic, meaning it is repelled by the external magnetic field as all electrons in the sodium and chloride ions are paired.
- \( \text{CuSO}_4 \) is paramagnetic; copper in the \( \text{Cu}^{2+} \) state has unpaired electrons, leading to attraction to the magnetic field.
Therefore, \( \text{NaCl} \) is the correct answer, as its diamagnetic nature causes it to be repelled.
Match List-I with List-II
\[\begin{array}{|l|l|} \hline \text{List-I (Physical Quantity)} & \text{List-II (Units)} \\ \hline \text{(A) Magnetic field} & \text{(I) J T\(^{-1}\)} \\ \hline \text{(B) Magnetic moment} & \text{(II) T m A\(^{-1}\)} \\ \hline \text{(C) Pole strength} & \text{(III) J T\(^{-1}\) m\(^{-1}\)} \\ \hline \text{(D) Permeability of free space} & \text{(IV) Wb m\(^{-2}\)} \\ \hline \end{array}\]Choose the correct answer from the options given below: