EXPLORING MAGNETS – Class 6 : Science
SUMMARY
1. Discovery of Magnets
The word magnet comes from Magnesia, a place in Greece.
Lodestone (a natural magnet) was the first discovered magnet.
2. Types of Magnets
Natural Magnet – Found in nature (example: lodestone).
Artificial Magnets – Made by humans in different shapes like:
Bar magnet
Horseshoe magnet
Cylindrical magnet
3. Properties of Magnets
Magnets attract materials like iron, nickel, and cobalt.
They have two poles – North Pole and South Pole.
Like poles repel, unlike poles attract.
The poles are the strongest parts of a magnet.
A freely suspended magnet always points in the North–South direction.
4. Care of Magnets
Magnets lose strength if they are heated, hammered, or dropped.
Magnets should be stored with keepers (soft iron bars) to protect their strength.
5. Uses of Magnets
In compasses for finding direction.
In refrigerator doors and locks.
In toys and machines.
For separating iron pieces from waste.
In electric motors, speakers, and microphones.
SHORT QUESTION AND ANSWER
Q: From which word is the term “magnet” derived?
A: From Magnesia
Q: What is lodestone?
A: A natural magnet
Q: Where was lodestone first discovered?
A: In Magnesia (Greece)
Q: Who first used magnets for navigation?
A: Chinese sailors
Q: What is a natural magnet?
A: A magnet found in nature (example: lodestone)
Q: What are artificial magnets?
A: Man-made magnets of different shapes
Q: Give two examples of artificial magnets?
A: Bar magnet, horseshoe magnet
Q: Which magnet is shaped like a U?
A: Horseshoe magnet
Q: Which magnet is long and rectangular?
A: Bar magnet
Q: Which magnet is round and tube-like?
A: Cylindrical magnet
Q: How many poles does a magnet have?
A: Two poles
Q: Name the poles of a magnet?
A: North Pole and South Pole
Q: Where is the magnetic force the strongest?
A: At the poles
Q: What happens when like poles are brought close?
A: They repel
Q: What happens when unlike poles are brought close?
A: They attract
Q: Which direction does a freely suspended magnet point?
A: North–South direction
Q: What materials are attracted by magnets?
A: Iron, nickel, and cobalt
Q: Are plastics attracted to magnets?
A: No
Q: Are aluminium and copper magnetic?
A: No
Q: Name one object in our home that contains magnets?
A: Refrigerator door
Q: What happens if a magnet is heated?
A: It loses its magnetism
Q: What happens if a magnet is hammered?
A: It loses strength
Q: What happens if a magnet is dropped?
A: It loses strength
Q: What is used to store bar magnets safely?
A: Keepers (soft iron bars)
Q: Why should magnets not be placed near mobiles or TVs?
A: They can damage them
Q: What instrument uses a magnet to show direction?
A: Compass
Q: Who uses a compass?
A: Sailors, travelers, and explorers
Q: Which household item uses magnets in its door?
A: Refrigerator
Q: Name one toy that uses magnets?
A: Magnetic car (or magnetic chess)
Q: Which machines use magnets?
A: Electric motors
Q: Where are magnets used in music systems?
A: In speakers and microphones
Q: How are magnets used in hospitals
A: In MRI machines
Q: How are magnets used in industries?
A: To separate iron from waste
Q: Which scientific tool uses magnets for study of Earth?
A: Compass
Q: Name one magnet used in doors and locks?
A: Magnetic latch
Q: Can magnets attract paper?
A: No
Q: Can a magnet lose its power over time?
A: Yes
Q: Can magnets work under water?
A: Yes
Q: Are all metals magnetic?
A: No
Q: Which pole of a magnet points towards Earth’s North?
A: The North Pole of the magnet
LONG QUESTION & ANSWER
Q: How was the first magnet discovered and what was it called?
A: Around 2000 years ago, in a place called Magnesia (in Greece), people discovered a stone that could attract iron. This stone was called lodestone. Lodestone is a natural magnet. The word “magnet” comes from Magnesia.
Q: Explain the story of how Chinese sailors used magnets?
A: Chinese sailors noticed that a freely suspended lodestone always pointed in the same direction – North and South. They began to use it for navigation at sea. This was the first use of a compass in history.
Q: What are natural and artificial magnets Give examples?
A: Natural magnets are those found in nature, such as lodestone. Artificial magnets are man-made magnets prepared in laboratories. They can be made into different shapes such as bar magnet, horseshoe magnet, and cylindrical magnet.
Q: Describe the shapes of artificial magnets with examples?
A: Artificial magnets can be shaped differently for various uses:
Bar magnet: long rectangular shape
Horseshoe magnet: U-shaped, strong force at the poles
Cylindrical magnet: tube-like shape
Disc magnet: round and flat
Each shape is used according to the need.
Q: What are magnetic poles?
A: Every magnet has two ends called poles – North Pole and South Pole. The magnetic force is strongest at the poles.
Q: State the law of magnetism with examples?
A: Like poles repel each other (North–North or South–South). Unlike poles attract each other (North–South). Example: When the North pole of one magnet is brought near the South pole of another, they attract.
Q: What happens when a magnet is freely suspended?
A: A freely suspended magnet always comes to rest in the North–South direction. This property is used in making a compass.
Q: Name the magnetic and non-magnetic materials with examples?
A:Magnetic materials: Attracted to magnets (iron, nickel, cobalt).
Non-magnetic materials: Not attracted to magnets (wood, plastic, copper, aluminium).
Q: Explain the strength of a magnet at different places?
A: The magnetic force is strongest at the poles and weakest in the middle of the magnet. For example, if pins are placed near a bar magnet, they will collect more at the ends.
Q: How is a compass made and used?
A: A compass is a small box containing a magnetized needle that can rotate freely. The needle always points North–South. It is used by sailors, travelers, and explorers for finding directions.
Q: Explain the uses of magnets in our daily life?
A: Magnets are used in refrigerator doors, toys, magnetic latches, doorbells, speakers, microphones, television, mobile phones, and in compasses for navigation.
Q: How are magnets used in industries?
A: Magnets are used in industries to separate iron objects from other materials. For example, in scrap yards, magnets help in picking up iron from waste.
Q: How are magnets used in medical science?
A: Magnets are used in MRI (Magnetic Resonance Imaging) machines, which help doctors to see inside the human body for diagnosis.
Q: Give five uses of magnets in machines and appliances?
A: Magnets are used in electric motors, generators, loudspeakers, microphones, mobile phones, and door latches.
Q: How should we store bar magnets?
A: Bar magnets should be stored in pairs with their opposite poles facing each other and separated by a piece of soft iron called a keeper. This prevents them from losing strength.
Q: Why should magnets not be dropped or hammered?
A: Dropping or hammering disturbs the alignment of tiny magnetic particles inside the magnet, which causes loss of magnetism.
Q: Why should magnets be kept away from electronic devices?
A: Strong magnets can damage electronic devices like mobiles, TVs, computers, and radios by disturbing their circuits.
Q: What happens when a magnet is heated or cooled?
A: Heating a magnet reduces or destroys its magnetism, while cooling can help regain it in some cases.
Q: How can magnets lose their strength List reasons?
A: Magnets lose strength if they are dropped, hammered, heated, or not stored properly with keepers.
Q: Write an experiment to show that magnets attract only some materials?
A: Take objects like pins, eraser, coin, plastic, and a nail. Bring a magnet close. Pins and nails are attracted (magnetic), while eraser and plastic are not (non-magnetic). This shows magnets attract only certain materials.
Q: Write an experiment to show poles of a magnet?
A: Place iron filings on a paper and keep a bar magnet below it. Filings gather more at the ends (poles) and less in the middle, proving that poles are the strongest parts of a magnet.
Q: Write an activity to show attraction and repulsion of poles?
A: Bring the North pole of one bar magnet close to the North pole of another – they repel. Bring the North pole close to the South pole – they attract. This proves the law of magnetism.
Q: How can you make a magnet at home?
A: Take an iron needle and rub one pole of a bar magnet along it several times in the same direction. The needle becomes a temporary magnet.
Q: Differentiate between temporary and permanent magnets?
A:Temporary magnet: Made easily but loses magnetism quickly (like a pin magnetized by rubbing).
Permanent magnet: Retains magnetism for a long time (bar magnet, horseshoe magnet).
Q: Compare natural magnets and artificial magnets?
A: Natural magnets occur in nature (lodestone) and are irregular in shape. Artificial magnets are man-made, can be shaped, and are stronger (bar, horseshoe, disc).
Q: State the differences between magnetic and non-magnetic materials?
A: Magnetic materials like iron, cobalt, and nickel are attracted by magnets, while non-magnetic materials like plastic, wood, and aluminium are not.
Q: Why are magnets important in modern technology?
A: Magnets are used in electricity generation, medical diagnosis, electronic devices, industries, transportation (maglev trains), and communication systems.
Q: Write a short note on magnetic separation in industries?
A: In factories, magnets are used to separate iron particles from mixtures like scrap or food grains. A moving belt with magnets collects only iron particles, leaving the rest.
Q: Write the main differences between poles and middle of a magnet?
A: At the poles, magnetic force is maximum, while at the middle it is minimum. This is proved by the iron filings experiment.
Q: Why is horseshoe magnet stronger than bar magnet?
A: In a horseshoe magnet, both poles are closer to each other. This concentrates the magnetic force and makes it stronger than a bar magnet.
MCQS:CHOOSE THE CORRECT ANSWER:
The word magnet comes from:
a) India
b) Magnesia
c) China
d) Africa
Answer: b) Magnesia
The first natural magnet discovered was:
a) Bar magnet
b) Lodestone
c) Horseshoe magnet
d) Compass
Answer: b) Lodestone
Materials attracted by magnets are called:
a) Non-magnetic
b) Magnetic
c) Plastic
d) Wood
Answer: b) Magnetic
Which of the following is magnetic?
a) Iron
b) Copper
c) Aluminium
d) Plastic
Answer: a) Iron
A magnet always has:
a) One pole
b) Two poles
c) Three poles
d) Four poles
Answer: b) Two poles
Poles of a magnet are located at:
a) Middle
b) Ends
c) Everywhere equally
d) Nowhere
Answer: b) Ends
The poles of a magnet are:
a) Equally strong
b) Strongest at the middle
c) Strongest at the ends
d) Weakest at the ends
Answer: c) Strongest at the ends
Like poles of a magnet:
a) Attract each other
b) Repel each other
c) Do not interact
d) Change polarity
Answer: b) Repel each other
Unlike poles of a magnet:
a) Repel each other
b) Attract each other
c) Break into pieces
d) Rotate
Answer: b) Attract each other
A freely suspended magnet always comes to rest in:
a) East–West direction
b) North–South direction
c) North–East direction
d) Random direction
Answer: b) North–South direction
The device used to find directions is:
a) Thermometer
b) Compass
c) Telescope
d) Microscope
Answer: b) Compass
Magnets lose strength when:
a) Heated
b) Hammered
c) Dropped
d) All of these
Answer: d) All of these
Natural magnet is also called:
a) Lodestone
b) Compass
c) Horseshoe
d) Iron piece
Answer: a) Lodestone
Artificial magnets can be:
a) Bar magnets
b) Horseshoe magnets
c) Disc magnets
d) All of these
Answer: d) All of these
A magnet is used in:
a) Electric motors
b) Speakers
c) Door locks
d) All of these
Answer: d) All of these
Which is NOT magnetic?
a) Iron
b) Nickel
c) Plastic
d) Cobalt
Answer: c) Plastic
Magnets should be stored with:
a) Wooden sticks
b) Keepers
c) Plastic boxes
d) Rubber bands
Answer: b) Keepers
A bar magnet has poles at:
a) Ends
b) Middle
c) One end only
d) Random spots
Answer: a) Ends
The Earth itself behaves like:
a) A bar magnet
b) A compass
c) A stone
d) A battery
Answer: a) A bar magnet
The south pole of a magnet points towards:
a) Earth’s south
b) Earth’s north
c) East
d) West
Answer: b) Earth’s north
Which of the following is used in compasses?
a) Iron rod
b) Magnetic needle
c) Copper wire
d) Plastic
Answer: b) Magnetic needle
Breaking a bar magnet into two pieces gives:
a) One magnet only
b) Two magnets with poles
c) No magnets
d) A poleless magnet
Answer: b) Two magnets with poles
Who discovered the first magnet?
a) Newton
b) An old shepherd named Magnes
c) Galileo
d) Edison
Answer: b) An old shepherd named Magnes
The area around a magnet where its effect is felt is called:
a) Magnetic force
b) Magnetic field
c) Magnetic area
d) Energy zone
Answer: b) Magnetic field
The north-seeking pole of a magnet is called:
a) North pole
b) South pole
c) East pole
d) West pole
Answer: a) North pole
Which of the following is NOT an artificial magnet shape?
a) Horseshoe
b) Bar
c) Sphere
d) Disc
Answer: c) Sphere
A compass needle is made of:
a) Copper
b) Iron
c) Steel
d) Aluminium
Answer: c) Steel
If a magnet is repeatedly dropped, it will:
a) Gain strength
b) Lose strength
c) Remain the same
d) Become longer
Answer: b) Lose strength
The property of a magnet to align in north-south direction is used in:
a) Maps
b) Compasses
c) Rulers
d) Globes
Answer: b) Compasses
Which is a temporary magnet?
a) Bar magnet
b) Lodestone
c) Electromagnet
d) Compass
Answer: c) Electromagnet
The strength of a magnet is maximum at:
a) Its middle
b) Its poles
c) Anywhere
d) Nowhere
Answer: b) Its poles
Which one is not a use of magnets?
a) ATM cards
b) Doorbells
c) Electric motors
d) Cooking food
Answer: d) Cooking food
Artificial magnets are made from:
a) Stone
b) Plastic
c) Iron or steel
d) Aluminium
Answer: c) Iron or steel
The Earth’s magnetic field helps in:
a) Playing games
b) Finding direction
c) Cleaning clothes
d) Cooking
Answer: b) Finding direction
An example of a natural magnet is:
a) Lodestone
b) Bar magnet
c) Horseshoe magnet
d) Compass
Answer: a) Lodestone
If a bar magnet is suspended freely, one end always points towards:
a) West
b) North
c) South
d) East
Answer: b) North
Which scientist explained Earth as a big magnet?
a) Newton
b) Gilbert
c) Faraday
d) Einstein
Answer: b) Gilbert
Which of these is NOT used in storing magnets?
a) Keepers
b) Wooden blocks
c) Iron strips
d) Bar magnets
Answer: b) Wooden blocks
The magnetic property disappears when the magnet is:
a) Burnt
b) Hammered
c) Heated strongly
d) All of these
Answer: d) All of these
Magnetic substances are:
a) Iron, nickel, cobalt
b) Copper, brass, silver
c) Plastic, glass, wood
d) All metals
Answer: a) Iron, nickel, cobalt
