Class 6 Chapter 13 Long Qa Science Cbse Ncert

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Extra 20 important long questions and answers from Chapter:13 Fun with Magnets of Class 6 Science (CBSE):-

1. What are the different types of magnets? Explain with examples.

Answer:
Magnets can be classified into two main types:

Natural Magnets:

Found in nature and have natural magnetic properties.

Example:

Lodestone (Magnetite)

Artificial Magnets:

Man-made magnets that come in different shapes.

Examples:

Bar magnet, Horseshoe magnet, U-shaped magnet, Ring magnet

Temporary Magnets:

Made by rubbing iron with a magnet or using electricity.

Example:

Electromagnets

used in cranes.

Permanent Magnets:

Retain their magnetism for a long time.

Example:

Bar magnets, Alnico magnets

Electromagnets:

Created by passing an electric current through a coil.

Example:

Electric bells, motors

2. Explain the properties of a magnet.

Answer:

Attractive Property:

Magnets attract iron, nickel, cobalt, and other magnetic materials.

Repulsion Property:

Like poles repel each other, and unlike poles attract each other.

Directive Property:

A freely suspended magnet always aligns itself in the

North-South direction

Magnetic Poles:

Every magnet has two poles—

North Pole and South Pole

Indivisibility:

If a magnet is broken into two pieces, each piece forms a new magnet with both poles.

Magnetic Field:

The region around a magnet where its effect is felt is called the

magnetic field

3. How do magnets lose their magnetism?

Answer:

Heating:

Excessive heat destroys the arrangement of magnetic domains, demagnetizing the magnet.

Hammering:

Striking a magnet repeatedly disrupts its magnetic alignment.

Dropping from a height:

Dropping a magnet weakens its internal structure, causing loss of magnetism.

Improper Storage:

If magnets are not stored with keepers (iron strips), they may lose their magnetism.

Electric Current:

Strong electric currents passing nearby can interfere with magnetic properties.

Rusting:

Rust formation on a magnet can weaken its magnetic force over time.

4. What are magnetic and non-magnetic materials? Give examples.

Answer:

Magnetic Materials:

These are materials that are attracted by a magnet.

Examples:

Iron, Nickel, Cobalt, Steel

Non-Magnetic Materials:

These materials are not attracted by a magnet.

Examples:

Wood, Plastic, Paper, Rubber, Copper,

Aluminium

Magnetic materials contain

domains

that align with a magnet’s field.

Non-magnetic materials lack such

domains

, so they do not respond to magnets.

Magnetic materials are used in making

electromagnets, transformers, and electric motors

Non-magnetic materials are used as

insulators in electrical appliances

5. What is a magnetic field? How can we see it?

Answer:

magnetic field

is the area around a magnet where its force is felt.

It is strongest near the

poles

of a magnet.

Magnetic fields can be

visualized using iron filings

sprinkled around a magnet.

The filings arrange themselves along

curved lines

, showing the shape of the field.

compass needle

placed near a magnet aligns with the field direction.

Magnetic fields are used in

MRI machines, electric motors, and generators

6. Explain the working of a magnetic compass.

Answer:

magnetic compass

is a device used to find directions.

It consists of a

magnetized needle

that is free to rotate.

The needle always aligns in the

North-South direction

due to Earth's magnetic field.

The compass is used in

navigation by sailors, pilots, and hikers

It works because the Earth acts like a

giant magnet

with a magnetic field.

Magnetic compasses are affected by nearby

electromagnets and iron objects

7. Why does Earth behave like a magnet?

Answer:

The Earth has a

molten iron core

, which creates a magnetic field.

This field extends into space and protects us from

solar radiation

The Earth's magnetic poles are

not exactly at the geographic poles

The

North Pole of a magnet points to the Earth's North

, which is actually a magnetic south pole.

This property allows

compasses to work

by aligning in the North-South direction.

Scientists use Earth's magnetism to study

continental drift and geological activities

8. How can you make a magnet at home?

Answer:

Take an

iron nail

and a

strong bar magnet

Rub the

magnet along the nail in one direction

about 20-30 times.

The nail will become a

temporary magnet

and attract iron filings.

This happens due to the

alignment of magnetic domains

in the iron nail.

The effect lasts for a short time unless

continuously magnetized

This process is called

magnetization by rubbing

9. What are the uses of magnets in daily life?

Answer:

Electric Motors

– Used in fans, washing machines, and refrigerators.

Magnetic Compass

– Used for navigation.

Electromagnets

– Used in cranes to lift heavy metal objects.

Speakers and Microphones

– Use magnets to produce sound.

Magnetic Locks

– Used in doors and cupboards.

Medical Uses

– MRI machines use strong magnets to scan the human body.

10. How are electromagnets different from permanent magnets?

Answer:

Feature	Electromagnet	Permanent Magnet
Made of	Coil of wire around an iron core	Iron, nickel, cobalt
Magnetism	Temporary, works only when current flows	Permanent
Strength	Can be changed by increasing current	Fixed strength
Uses	Electric bells, cranes, speakers	Compasses, fridge magnets

Electromagnets are

stronger and can be turned on/off

Permanent magnets are

always magnetic

but cannot be controlled.

Electromagnets are used in

electric motors and MRI machines

Permanent magnets are used in

fridge doors and loudspeakers

The

strength of an electromagnet

depends on the number of coils and current flow.

Electromagnets are used in

junkyard cranes to lift scrap metal

11. What happens when a magnet is broken into pieces?

Answer:

If a

bar magnet is broken

, each piece will still have a

North and South Pole

The

magnetic properties remain intact

in both pieces.

No matter how many times it is broken, a

single pole cannot be obtained

This proves that magnetic poles

always exist in pairs

The strength of each smaller magnet

reduces

compared to the original magnet.

Scientists believe that even

tiny atoms have magnetic properties

inside them.

12. What are the safety measures for storing magnets?

Answer:

Bar magnets

should be stored in pairs with their opposite poles facing each other.

piece of soft iron (keeper)

should be placed at both ends.

Magnets should be kept

away from heat

to avoid demagnetization.

Magnets should not be

dropped or hammered

, as it weakens their strength.

They should be stored

away from electronic devices

like mobile phones, computers, and TVs.

Horseshoe magnets should be stored

with a metal keeper across their poles

13. Explain how iron filings can show the shape of a magnetic field.

Answer:

Place a

bar magnet on a sheet of paper

Sprinkle

iron filings

around the magnet.

Gently tap the paper so the filings arrange themselves in a

pattern

The filings align along

curved lines

that show the

magnetic field lines

The lines are

denser at the poles

, showing that the field is stronger there.

This experiment helps visualize the

invisible magnetic field

14. Why do like poles repel and unlike poles attract?

Answer:

When two

like poles (N-N or S-S)

come close, their magnetic fields push each other away.

This is due to the

repelling force

between similar magnetic fields.

When

opposite poles (N-S)

come close, their magnetic fields combine and pull together.

This attraction happens because their field lines move in the

same direction

This property is called the

law of magnetic poles

It is used in real-world applications like

levitating trains (Maglev trains)

15. What are the differences between magnetic and non-magnetic materials?

Answer:

Property	Magnetic Materials	Non-Magnetic Materials
Example	Iron, Nickel, Cobalt	Wood, Plastic, Rubber
Attraction by Magnet	Yes	No
Magnetic Field Effect	Gets magnetized	No effect
Used in	Motors, speakers, electromagnets	Insulators, plastic objects

Magnetic materials have

aligned atomic magnetic domains

Non-magnetic materials have

randomly arranged atomic domains

Magnets are made using

ferromagnetic

materials like iron.

Gold, silver, and copper

are non-magnetic even though they are metals.

Magnetic materials are widely used in

electrical and industrial applications

Non-magnetic materials are used in

insulation and non-electronic applications

16. How does a Maglev train use magnets?

Answer:

Maglev (Magnetic Levitation) trains use

strong electromagnets

to float above the tracks.

The

repulsion and attraction

between magnets push the train forward.

Since the train

does not touch

the track,

friction is reduced

, allowing it to move faster.

Magnets are placed in both the

train and the track

for levitation.

This technology is

faster and quieter

than regular trains.

Examples:

Shanghai Maglev (China),

SCMaglev

(Japan)

17. What is an electromagnet? How does it work?

Answer:

electromagnet

is a temporary magnet created by

passing electricity

through a coil.

It is made by

wrapping a wire around an iron core

and connecting it to a battery.

When the

current flows

, the iron becomes magnetized.

The magnetism disappears when the

current is switched off

Electromagnets are used in

electric bells, cranes, and MRI machines

The strength of an electromagnet depends on the

number of coils and the current flow

18. Explain how magnets are used in an electric bell.

Answer:

When the

switch is pressed

, electricity flows through the

electromagnet

The electromagnet attracts a

metal strip (armature)

, causing the bell to ring.

As the armature moves, the

circuit breaks

, and the electromagnet loses its power.

The armature returns to its original position,

reconnecting the circuit

This process repeats quickly, producing a

continuous ringing sound

Electromagnets allow electric bells to work

efficiently and repeatedly

19. What is the difference between a bar magnet and a horseshoe magnet?

Answer:

Feature	Bar Magnet	Horseshoe Magnet
Shape	Straight, rectangular	U-shaped
Magnetic Strength	Moderate	Stronger at the poles
Field Lines	Spread out evenly	Focused at ends
Common Uses	Compasses, fridge magnets	Motors, lifting objects
Attraction Power	Less concentrated	More concentrated

Horseshoe magnets have

higher strength

due to their curved shape.

Bar magnets have

uniform poles

and are commonly used in experiments.

Horseshoe magnets are used in

cranes and heavy lifting

Bar magnets are used in

compasses and science experiments

The field of a horseshoe magnet is

denser and more concentrated

at the poles.

Bar magnets are

easier to store and handle

20. What are some common uses of magnets in industries?

Answer:

Medical Industry:

Used in

MRI (Magnetic Resonance Imaging) machines

to scan internal organs.

Electronics:

Used in

TVs, speakers, and hard drives

for data storage.

Transportation:

Maglev trains

use powerful magnets for fast movement.

Scrap Industry:

Electromagnets help in

lifting heavy scrap metal

Power Generation:

Magnets are used in

electric generators and turbines

Security Systems:

Magnetic strips are used in

ATM cards and security locks