Q.1 Which of the following pairs is that of paramagnetic materials? CBSE 12th Physics Delhi Set 1 – 2024
(a) Copper and Aluminium
(b) Sodium and Calcium
(c) Lead and Iron
(d) Nickel and Cobalt
Q.2 Assertion (A) : Diamagnetic substances exhibit magnetism.
Reason (R) : Diamagnetic materials do not have permanent magnetic dipole moment. CBSE 12th Physics Outside Delhi Set 1 – 2023
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, but R is not the correct explanation of A.
C. A is true, but R is false.
D. A is false, but R is true.
Q.3 Which of the following has its permeability less than that of free space? CBSE 12th Physics Delhi Set 1 – 2023
(a) Copper
(b) Aluminium
(c) Copper Chloride
(d) Nickel
Explanation
Q.1 Paramagnetic are the materials that are feebly attracted to an external magnetic field. If a magnet is brought near these materials, these materials will get feebly magnetise towards it. Sodium and Calcium are paramagnetic materials.
Q.2 The assertion is true. Diamagnetic substance shows faint repulsion. It is a property of magnetism. So, assertion is true. The above property is observed in the substances which have even number of electrons in each atom/molecule. Electrons with opposite spins form pairs and so no net dipole moment is generated. Diamagnetic substances are such substances and hence exhibit the above magnetic property. So, the reason is true it explains the assertion.
Q.3 It is negative for diamagnetic substance. Copper is diamagnetic substance.