Umakant Kondapure, Collin Fernandes, Nipun Bhatia, Vikram Bathula and, Ketki Deshpande Solutions for Chapter: Magnetism, Exercise 3: Competitive Thinking

The material of a permanent magnet has
 

A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When the current in the electromagnet is switched ON, then the diamagnetic rod is pushed up, out of the horizontal magnetic field. Hence, the rod gains gravitational potential energy. The work required to do this comes from
 

Core of electromagnets are made of ferromagnetic material which has

The use of study of hysteresis curve for a given material is to estimate the
 

An iron rod of length $L$ and magnetic moment $M$ is bent in the form of a semicircle. Now, its magnetic moment will be
 

The effective length of a magnet is $31.4 \mathrm{cm}$ and its pole strength is $0.8 \mathrm{A} \mathrm{m}$. The magnetic moment, if it is bent in the form of a semicircle is, in $\left(\mathrm{A} {\mathrm{m}}^2\right)$

When a ferromagnetic material is heated to a temperature above its Curie temperature, the material
 

Assertion: Susceptibility is defined as the ratio of intensity of magnetisation $I$ to magnetic intensity $H$.

Reason: Greater the value of susceptibility, smaller the value of intensity of magnetisation $I$.