MAGNETISM

The phenomenon related to attractive and directive properties is:

Answer: magnetism

Attraction is the surest test of magnetism:

Answer: False

Like poles of a magnet repel each other:

Answer: True

Materials which are attracted by magnets are:

Answer: ferromagnetic

Which is not a ferromagnetic material:

Answer: glass

Which is a ferromagnetic material:

Answer: cobalt

Which is not a property of a magnet:

Answer: assertive

In a magnet, the attraction is strongest:

Answer: at poles

Freely suspended magnet points in ____ direction.

Answer: north-south

Iron loses its magnetism easily.

Answer: True

Steel is a hard magnetic material.

Answer: True

A freely suspended magnet always points in north-south direction. This proves its:

Answer:  directive property

Pick the pair of magnetic substances.

Answer: nickel and cobalt

An example of a natural magnet is:

Answer: lodestone

For a given magnet :

Answer: both have the same strength

The magnetic lines of force of a bar magnet are:

Answer: continuous and non intersecting

Strength of magnetic field is shown by the density of magnetic lines of force.

Answer: True

Magnetic field is strong at the place where magnetic lines of force are:

Answer: dense

A magnetic material acquires temporary magnetic property in presence of another magnet near it due to:

Answer: induced magnetism

During magnetic induction, a magnetic pole induces _____ polarity on the near end of iron bar being induced.

Answer: opposite

The direction of magnetic field at a point on a magnetic field line is given by:

Answer: tangent

What kind of magnetic field is represented by parallel and equidistant lines?

Answer: uniform magnetic field

Several soft iron pins cling one below the other from the pole of a magnet due to:

Answer: induced magnetism

The field around a bar magnet is:

Answer: non uniform

Earth’s magnetic field at a small horizontal plane on the earth’s surface is:

Answer: uniform

Which is a magnetic material?

Answer: steel

Which is a magnetic material?

Answer: iron

Which is a non magnetic material?

Answer: zinc

Which is a non magnetic material?

Answer: magnesium

How can you find out which end of a magnet is the north pole?

Answer: put it near a compass

ELECTROMAGNETISM

Solenoid with soft iron core is:

Answer: electromagnet

A coil wound over soft iron piece is:

Answer: solenoid

An electro magnet is:

Answer: temporary magnet

When current through coil stops flowing, the coil remains an electromagnet.

Answer: False

Iron is used to make permanent magnet.

Answer: True

The magnetic field around a current carrying coil:

Answer:  Lasts as long as current flows

Strength of magnetic field in solenoid can be increased by:

Answer: increasing the number of turns

Strength of magnetic field in solenoid can be increased by:

Answer:  increasing current strength.

Strength of magnetic field in solenoid can be increased by:

Answer: increasing current strength

Which is not a use of electromagnet:

Answer: study of mechanical properties

Strength of an electromagnet can be determined using:

Answer: magnetic compass

Which of the following uses electromagnetic effect?

Answer: washing machine

If current direction flowing through a wire is reversed the direction of magnetic field will:

Answer: will get reversed

What is the difference between permanent magnet and electromagnet?

Answer: Electromagnets can be turned off

The polarity of an electromagnet can be reversed by reversing the direction of current in the solenoid.

Answer: True

The magnetic polarity at the two ends of a horse shoe electromagnet depends on:

Answer: direction of current at the two ends

What kind of magnet can be turned on and off?

Answer: Electromagnet

ELECTRIC BELL

A device that works on the basis of magnetic effects of current is:

Answer: electric bell

In an electric bell electrical energy is finally converted into:

Answer: sound energy

Electric bell is application of:

Answer: electromagnet and magnetic effect of current

Which is incorrect for working of electric bell?

Answer: the bell rings when switch is not pressed

In an electric bell, when electromagnet is demagnetised, the hammer strikes the gong.

Answer: False

On magnetisation of electromagnet the hammer of electric bell strikes the gong.

Answer: True

Magnet used in electric bell is:

Answer: horse shoe electromagnet

In an electric bell when the electromagnet attracts the armature, it demonstrates conversion of electrical energy to:

Answer: mechanical energy

In an electric bell when the armature hits the gong, it demonstrates conversion of electrical energy to:

Answer: sound energy

In an electric bell to increase the volume of sound you have to:

Answer: increase current flowing through circuit

The purpose of armature in electric bell is to:

Answer: make and break circuit

What brings back the armature to original position when circuit is broken?

Answer: spring

The frequency of ringing of an electric bell can be altered by adjusting:

Answer: hammer and armature