Electricity and Magnetism - 2 PHYSICS - Electricity and Magnetism - 2

The place around a magnet where its influence can be detected is called:

The substance which form a strong temporary magnet is:

Nickel is a :

The surest test of magnet is:

The magnetic strength of a bar magnet is :

Draw a clearly labelled diagram, to show how a steel bar is magnetised by a divided touch method. A written description is not required.

Draw the magnetic flux pattern near a bar magnet placed with its axis in the magnetic meridian and the south pole pointing towards geographic north.

The figure shows a freely suspended magnet in rest position. Copy the diagram and on it show :
(a) Angle of declination
(b) Angle in dip

Explain, why steel is used in preference to soft iron for making permanent magnets while soft iron is used in preference to steel for making electromagnets.

There are two knitting needles. One of them is magnetised. How will you find out which one is magnetised, if no other magnet is available?

(a) Explain the mechanism by which unmagnetised iron nails get attracted to a magnet when brought near it.
(b) State any two properties of magnet.

1. Name the metal used for E and F.
2. Why are E and F placed in contact with the poles of the magnets as shown in the diagram?
3. Mark on the diagram the poles of the second magnet,
4. What is the material of darkened part?

Define : Isogonic line, agonic line isoclinic line.

What do you meant by the term pole of a magnet? Magnetically speaking, what is the difference between a piece of brass, a piece of soft iron and a piece of lode-stone?

What do you understand by the term magnetic declination?

(a) What are magnetic keepers? What are they used for?
(b) Explain the 'molecular theory' of magnetism with the help of a diagram.

Define the terms magnetic declination and dip with reference to freely suspended magnet.
(a) What do you understand by the terms magnetic meridian and geographic meridian?
(b) At what places on the earth will the angle of dip be (1) maximum and (2) minimum?

(a) Since every iron atom is a tiny magnet, why are not all iron bar magnets?
(b) If a magnet is carefully broken into two pieces as shown in figure (i), how does the magnetic strength of each piece compare with that of original magnet? If another magnet is carefully broken in half along its long axis shown in figure (ii), how would the strength of each piece compare with that of original magnet?

Draw lines of force surrounding a bar magnet when it is placed in the magnetic meridian with its
(a) north pole pointing geographic, north
(b) north pole pointing geographic south.