Fun With Magnets

The process by which an object exerts a force on another that is directed towards the source of the force is called attraction. The process by which the object forces another away from itself is called repulsion.

What will happen in the following scenario?

• A will be repelled by B.

• B will be attracted to A.

• The magnetic field lines will not bend towards each other.

• The magnetic field lines will bend away from each other.

There are some properties of magnets which help us to understand them better.

Which of the following is not a property of magnets?

• Magnets can’t exert their influence through air and water.

• A freely suspended magnet always comes to rest in the north-south direction.

• Like poles repel, whereas unlike poles attract each other.

• None of these.

The materials which are attracted towards magnets are called magnetic substances.

Which of the following is not a magnetic substance?

• Nickel

• Cobalt

• Aluminium

• Gadolinium

There are three types of magnets — permanent magnets, temporary magnets and electromagnets. The magnets that remain magnetic until they are severely damaged are called permanent magnets.

Which of the following is not used to make permanent magnets?

• Soft iron

• Hard iron

• Steel

• Alnico

There are many types of magnetic substances. They may be paramagnetic, diamagnetic, ferromagnetic materials or ferrites.

What are paramagnetic materials?

• The materials which are not strongly attracted towards a magnet.

• The materials which are repelled by a magnet.

• The materials which are strongly attracted by a magnet.

• The materials that occupy an intermediate position between ferromagnetic and non-ferromagnetic materials.

Magnetic field can be measured using a magnetometer.

The official SI unit for measuring magnetic field strength is

• Tesla

• Volt

• Ampere

• Hertz

It is a property of magnets to always come into rest in the north-south direction.

Why is it so?

• The North Pole of the magnet points towards the geographical South Pole because it is attracted by the geographical North Pole.

• The South Pole of the magnet points towards the geographical North Pole because it is attracted by the geographical South Pole.

• The North Pole of the magnet points towards the geographical North Pole because it is attracted by the earth’s magnetic South Pole.

• The South Pole of the magnet points towards the geographical South Pole because it is repelled by the geographical North Pole.

It has been proved that our body is indeed magnetic in the sense that the body is a source of magnetic fields.

The following investigation (study) uses the body’s natural magnetic properties to produce detailed images of any part of the body:

• Magnetic Resistance Imaging

• Magnetic Resonance Imaging

• Magnetic Receptor Imaging

• Magnetic Repellent Imaging

Magnets are used widely in daily life. They are used in pencil boxes, doors, refrigerators, speakers, earphones, televisions, computers etc.

The name of the train transportation system that uses magnets is:

• Magnet train

• Magneto-train

• Magnes-train

• Maglev train

There are certain precautions to be taken while handling magnets.

Following are the precautions to be observed while handling magnets except:

• They should not be heated.

• They should be kept away from things televisions, computers etc.

• They should not be hammered.

• They should not be dropped in water.