S L Arora Solutions for Chapter: Magnetism, Exercise 3: SHORT ANSWER CONCEPTUAL PROBLEMS

Three identical specimens of magnetic materials Nickel, Antimony, Aluminium are kept in a uniform magnetic field. Draw the modification in the field lines in each case. Justify your answer.

What are permanent magnets ? State, briefly, an efficient way of making a permanent magnet. Write two properties to select suitable materials for making permanent magnets.

The susceptibility of a magnetic material is $-2.6\times {10}^{-5}$. Identify the type of magnetic material and state its two properties.

The susceptibility of a magnetic material is $2.6\times {10}^{-5}$. Identify the type of magnetic material and state its two properties.

The relative magnetic permeability of a magnetic material is 800. Identify the nature of magnetic material and state its two properties.

Draw magnetic field lines when a (i) diamagnetic (ii) paramagnetic substance is placed in an external magnetic field. Which magnetic property distinguishes this behaviour of the field lines due to the two substances?

Briefly explain how will you demagnetise a piece of iron completely.

Cosmic rays are charged particles that bombard earth's atmosphere from outer space. Why do the north and south magnetic poles of earth receive more low-energy cosmic rays than the magnetic equator.