Question

A superconductor exhibits perfect:
A) Ferrimagnetism
B) Ferromagnetism
C) Paramagnetism
D) Diamagnetism

Answer 1

Hint: Superconductor is a substance that conducts electricity without resistance when it becomes colder than a critical temperature.
Superconductors oppose the magnetic field thus, superconductors are highly diamagnetic.
Using the above concept of superconductors we will define diamagnetism in more details.

Complete solution:
Superconductors: Material which has resistance equal to zero, when cooled to a certain critical temperature. Below the certain critical temperature superconductors show the effect called the Meissner effect, where the superconductor expels all the magnetic fields.
Let's check the properties of each option given in the question, which one will match with the superconductors.
Ferromagnetism: Ferrimagnetic material is the one that has populations of atoms with opposing magnetic moments, the opposing moments are unequal and has a spontaneous magnetization remains.
Thus, properties do not match with the superconductors.
Ferromagnetism: Ferromagnetism is the basic mechanism by which certain materials form permanent magnets. Ferromagnetism is the strongest type and is responsible for the common phenomenon of magnetism in magnets encountered everyday.
Thus, properties do not match with the superconductors.
Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, induced magnetic fields in the direction of the applied magnetic field.
Properties of paramagnetic material do not match with superconductors.
Diamagnetism: Diamagnetic materials are repelled by a magnetic field, an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force.
Thus, properties of superconductors match with the properties of diamagnetism.

Hence, option (D) is correct.

Note: Superconductors have many applications such as: Levitating trains, Nuclear fusion, MRI scanner, small particle accelerator in health, superconducting quantum interference device. Superconductors levitate over magnets. Superconductors don't let the magnetic field pass through it but acts as a magnet pointing the opposite way which repels the real magnet.