Page 1
Chapter 15: Fun with Magnets
EXERCISE [PAGE 111]
Exercise | Q 1.1 | Page 111
How will you do this?
Determine whether a material is magnetic or non-magnetic.
SOLUTION
If a material sticks to a magnet, then it is a magnetic material otherwise it is a non -
magnetic material.
Exercise | Q 1.2 | Page 111
How will you do this?
Explain that a magnet has a certain magnetic field.
SOLUTION
A magnet has a certain magnetic field which can be demonstrated using the below
activity.
Take a drawing cardboard and sprinkle some iron filings on it. Notice the position of the
iron filings as a whole. Now, take a bar magnet and slowly bring it below the cardboard.
You will observe that the iron filings tend to attract towards the magnet and align
themselves as shown.
It represents that the magnet exerts a force around its body with a stronger force near
the two poles. Also, this regular pattern of the iron filings on the board represents the
lines of magnetic field. Thus, a magnet has a certain magnetic field which can be
represented by curved lines around a magnet.
Exercise | Q 1.3 | Page 111
How will you do this?
Find the north pole of a magnet.
Page 2
Chapter 15: Fun with Magnets
EXERCISE [PAGE 111]
Exercise | Q 1.1 | Page 111
How will you do this?
Determine whether a material is magnetic or non-magnetic.
SOLUTION
If a material sticks to a magnet, then it is a magnetic material otherwise it is a non -
magnetic material.
Exercise | Q 1.2 | Page 111
How will you do this?
Explain that a magnet has a certain magnetic field.
SOLUTION
A magnet has a certain magnetic field which can be demonstrated using the below
activity.
Take a drawing cardboard and sprinkle some iron filings on it. Notice the position of the
iron filings as a whole. Now, take a bar magnet and slowly bring it below the cardboard.
You will observe that the iron filings tend to attract towards the magnet and align
themselves as shown.
It represents that the magnet exerts a force around its body with a stronger force near
the two poles. Also, this regular pattern of the iron filings on the board represents the
lines of magnetic field. Thus, a magnet has a certain magnetic field which can be
represented by curved lines around a magnet.
Exercise | Q 1.3 | Page 111
How will you do this?
Find the north pole of a magnet.
SOLUTION
Tie a thread to the centre of a magnet and hang it from a stand as shown. Wait till the
magnet settles itself.
Exercise | Q 2.1 | Page 111
Which magnet will you use?
Iron is to be separated from trash.
SOLUTION
Electromagnet can be used to separate iron from trash.
Exercise | Q 2.2 | Page 111
Which magnet will you use?
You are lost in a forest.
SOLUTION
Bar magnet or loadstone can be used to find the direction in the forest. This is because
a bar magnet, when suspended freely, always rests in north-south direction.
Exercise | Q 2.3 | Page 111
Which magnet will you use?
A window shutter opens and shuts continuously in the wind.
SOLUTION
Permanent magnet can be used to stop the continuous shuttering of the window in the
wind.
Exercise | Q 3.1 | Page 111
Select the appropriate word and answer the question:
Page 3
Chapter 15: Fun with Magnets
EXERCISE [PAGE 111]
Exercise | Q 1.1 | Page 111
How will you do this?
Determine whether a material is magnetic or non-magnetic.
SOLUTION
If a material sticks to a magnet, then it is a magnetic material otherwise it is a non -
magnetic material.
Exercise | Q 1.2 | Page 111
How will you do this?
Explain that a magnet has a certain magnetic field.
SOLUTION
A magnet has a certain magnetic field which can be demonstrated using the below
activity.
Take a drawing cardboard and sprinkle some iron filings on it. Notice the position of the
iron filings as a whole. Now, take a bar magnet and slowly bring it below the cardboard.
You will observe that the iron filings tend to attract towards the magnet and align
themselves as shown.
It represents that the magnet exerts a force around its body with a stronger force near
the two poles. Also, this regular pattern of the iron filings on the board represents the
lines of magnetic field. Thus, a magnet has a certain magnetic field which can be
represented by curved lines around a magnet.
Exercise | Q 1.3 | Page 111
How will you do this?
Find the north pole of a magnet.
SOLUTION
Tie a thread to the centre of a magnet and hang it from a stand as shown. Wait till the
magnet settles itself.
Exercise | Q 2.1 | Page 111
Which magnet will you use?
Iron is to be separated from trash.
SOLUTION
Electromagnet can be used to separate iron from trash.
Exercise | Q 2.2 | Page 111
Which magnet will you use?
You are lost in a forest.
SOLUTION
Bar magnet or loadstone can be used to find the direction in the forest. This is because
a bar magnet, when suspended freely, always rests in north-south direction.
Exercise | Q 2.3 | Page 111
Which magnet will you use?
A window shutter opens and shuts continuously in the wind.
SOLUTION
Permanent magnet can be used to stop the continuous shuttering of the window in the
wind.
Exercise | Q 3.1 | Page 111
Select the appropriate word and answer the question:
If a bar magnet is hung by a thread tied at its center, its north pole becomes steady in
the direction of the _______ Pole of the earth.
(South, north, east, west)
SOLUTION
If a bar magnet is hung by a thread tied at its center, its north pole becomes steady in
the direction of the north pole of the earth.
Exercise | Q 3.2 | Page 111
Select the appropriate word and answer the question:
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two
places, ______ bar magnets are formed, and a total of _______ poles are formed.
(6,3,2)
SOLUTION
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two
places, 3 bar magnets are formed, and a total of 6 poles are formed.
Exercise | Q 3.3 | Page 111
Fill in the blanks with the appropriate word.
There is repulsion between the _____ poles of a magnet, and attraction between its
_____ poles.
(opposite, like.)
SOLUTION
There is repulsion between the like poles of a magnet, and attraction between
its opposite poles.
Exercise | Q 3.4 | Page 111
Fill in the blanks with the appropriate word.
When magnetic material is taken close to a magnet, the material acquires ________.
(permanent magnetism, induced magnetism)
SOLUTION
When magnetic material is taken close to a magnet, the material acquires induced
magnetism.
Exercise | Q 3.5 | Page 111
Fill in the blank with the appropriate word.
If a magnet attracts a piece of metal, that piece must be made of _______.
(any other metal but iron, magnetic material or iron, non-magnetic material)
SOLUTION
If a magnet attracts a piece of metal, that piece must be made of magnetic material or
iron.
Page 4
Chapter 15: Fun with Magnets
EXERCISE [PAGE 111]
Exercise | Q 1.1 | Page 111
How will you do this?
Determine whether a material is magnetic or non-magnetic.
SOLUTION
If a material sticks to a magnet, then it is a magnetic material otherwise it is a non -
magnetic material.
Exercise | Q 1.2 | Page 111
How will you do this?
Explain that a magnet has a certain magnetic field.
SOLUTION
A magnet has a certain magnetic field which can be demonstrated using the below
activity.
Take a drawing cardboard and sprinkle some iron filings on it. Notice the position of the
iron filings as a whole. Now, take a bar magnet and slowly bring it below the cardboard.
You will observe that the iron filings tend to attract towards the magnet and align
themselves as shown.
It represents that the magnet exerts a force around its body with a stronger force near
the two poles. Also, this regular pattern of the iron filings on the board represents the
lines of magnetic field. Thus, a magnet has a certain magnetic field which can be
represented by curved lines around a magnet.
Exercise | Q 1.3 | Page 111
How will you do this?
Find the north pole of a magnet.
SOLUTION
Tie a thread to the centre of a magnet and hang it from a stand as shown. Wait till the
magnet settles itself.
Exercise | Q 2.1 | Page 111
Which magnet will you use?
Iron is to be separated from trash.
SOLUTION
Electromagnet can be used to separate iron from trash.
Exercise | Q 2.2 | Page 111
Which magnet will you use?
You are lost in a forest.
SOLUTION
Bar magnet or loadstone can be used to find the direction in the forest. This is because
a bar magnet, when suspended freely, always rests in north-south direction.
Exercise | Q 2.3 | Page 111
Which magnet will you use?
A window shutter opens and shuts continuously in the wind.
SOLUTION
Permanent magnet can be used to stop the continuous shuttering of the window in the
wind.
Exercise | Q 3.1 | Page 111
Select the appropriate word and answer the question:
If a bar magnet is hung by a thread tied at its center, its north pole becomes steady in
the direction of the _______ Pole of the earth.
(South, north, east, west)
SOLUTION
If a bar magnet is hung by a thread tied at its center, its north pole becomes steady in
the direction of the north pole of the earth.
Exercise | Q 3.2 | Page 111
Select the appropriate word and answer the question:
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two
places, ______ bar magnets are formed, and a total of _______ poles are formed.
(6,3,2)
SOLUTION
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two
places, 3 bar magnets are formed, and a total of 6 poles are formed.
Exercise | Q 3.3 | Page 111
Fill in the blanks with the appropriate word.
There is repulsion between the _____ poles of a magnet, and attraction between its
_____ poles.
(opposite, like.)
SOLUTION
There is repulsion between the like poles of a magnet, and attraction between
its opposite poles.
Exercise | Q 3.4 | Page 111
Fill in the blanks with the appropriate word.
When magnetic material is taken close to a magnet, the material acquires ________.
(permanent magnetism, induced magnetism)
SOLUTION
When magnetic material is taken close to a magnet, the material acquires induced
magnetism.
Exercise | Q 3.5 | Page 111
Fill in the blank with the appropriate word.
If a magnet attracts a piece of metal, that piece must be made of _______.
(any other metal but iron, magnetic material or iron, non-magnetic material)
SOLUTION
If a magnet attracts a piece of metal, that piece must be made of magnetic material or
iron.
Exercise | Q 3.6 | Page 111
Fill in the blank with the appropriate word.
A magnet remains steady in a ________ direction.
(east-west, north-south)
SOLUTION
A magnet remains steady in a north-south direction.
Exercise | Q 4.1 | Page 111
Write the answer in your word.
How is an electromagnet made?
SOLUTION
For the construction of an electromagnet, we require an iron nail, a long insulated
copper wire, a battery and a switch.
The long insulated copper wire is first wound on the iron nail. Then the two free ends of
the wire is connected to the battery and the switch as shown. Now, when the switch is
turned on, current flows through the circuit. Due to this flow of current, the insulated
copper wire and iron nail acts as an electromagnet. Now, if iron pins are brought close
to this set-up, they stick to the iron nail.
As soon as the current stops flowing in the circuit, the iron nail loses magnetism and the
pins fall off.
Case: Switch open
Case: Switch close
Exercise | Q 4.2 | Page 111
Write the answer in your word.
Write the properties of a magnet.
Page 5
Chapter 15: Fun with Magnets
EXERCISE [PAGE 111]
Exercise | Q 1.1 | Page 111
How will you do this?
Determine whether a material is magnetic or non-magnetic.
SOLUTION
If a material sticks to a magnet, then it is a magnetic material otherwise it is a non -
magnetic material.
Exercise | Q 1.2 | Page 111
How will you do this?
Explain that a magnet has a certain magnetic field.
SOLUTION
A magnet has a certain magnetic field which can be demonstrated using the below
activity.
Take a drawing cardboard and sprinkle some iron filings on it. Notice the position of the
iron filings as a whole. Now, take a bar magnet and slowly bring it below the cardboard.
You will observe that the iron filings tend to attract towards the magnet and align
themselves as shown.
It represents that the magnet exerts a force around its body with a stronger force near
the two poles. Also, this regular pattern of the iron filings on the board represents the
lines of magnetic field. Thus, a magnet has a certain magnetic field which can be
represented by curved lines around a magnet.
Exercise | Q 1.3 | Page 111
How will you do this?
Find the north pole of a magnet.
SOLUTION
Tie a thread to the centre of a magnet and hang it from a stand as shown. Wait till the
magnet settles itself.
Exercise | Q 2.1 | Page 111
Which magnet will you use?
Iron is to be separated from trash.
SOLUTION
Electromagnet can be used to separate iron from trash.
Exercise | Q 2.2 | Page 111
Which magnet will you use?
You are lost in a forest.
SOLUTION
Bar magnet or loadstone can be used to find the direction in the forest. This is because
a bar magnet, when suspended freely, always rests in north-south direction.
Exercise | Q 2.3 | Page 111
Which magnet will you use?
A window shutter opens and shuts continuously in the wind.
SOLUTION
Permanent magnet can be used to stop the continuous shuttering of the window in the
wind.
Exercise | Q 3.1 | Page 111
Select the appropriate word and answer the question:
If a bar magnet is hung by a thread tied at its center, its north pole becomes steady in
the direction of the _______ Pole of the earth.
(South, north, east, west)
SOLUTION
If a bar magnet is hung by a thread tied at its center, its north pole becomes steady in
the direction of the north pole of the earth.
Exercise | Q 3.2 | Page 111
Select the appropriate word and answer the question:
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two
places, ______ bar magnets are formed, and a total of _______ poles are formed.
(6,3,2)
SOLUTION
If a bar magnet is cut into equal pieces by cutting it at right angles to its axis at two
places, 3 bar magnets are formed, and a total of 6 poles are formed.
Exercise | Q 3.3 | Page 111
Fill in the blanks with the appropriate word.
There is repulsion between the _____ poles of a magnet, and attraction between its
_____ poles.
(opposite, like.)
SOLUTION
There is repulsion between the like poles of a magnet, and attraction between
its opposite poles.
Exercise | Q 3.4 | Page 111
Fill in the blanks with the appropriate word.
When magnetic material is taken close to a magnet, the material acquires ________.
(permanent magnetism, induced magnetism)
SOLUTION
When magnetic material is taken close to a magnet, the material acquires induced
magnetism.
Exercise | Q 3.5 | Page 111
Fill in the blank with the appropriate word.
If a magnet attracts a piece of metal, that piece must be made of _______.
(any other metal but iron, magnetic material or iron, non-magnetic material)
SOLUTION
If a magnet attracts a piece of metal, that piece must be made of magnetic material or
iron.
Exercise | Q 3.6 | Page 111
Fill in the blank with the appropriate word.
A magnet remains steady in a ________ direction.
(east-west, north-south)
SOLUTION
A magnet remains steady in a north-south direction.
Exercise | Q 4.1 | Page 111
Write the answer in your word.
How is an electromagnet made?
SOLUTION
For the construction of an electromagnet, we require an iron nail, a long insulated
copper wire, a battery and a switch.
The long insulated copper wire is first wound on the iron nail. Then the two free ends of
the wire is connected to the battery and the switch as shown. Now, when the switch is
turned on, current flows through the circuit. Due to this flow of current, the insulated
copper wire and iron nail acts as an electromagnet. Now, if iron pins are brought close
to this set-up, they stick to the iron nail.
As soon as the current stops flowing in the circuit, the iron nail loses magnetism and the
pins fall off.
Case: Switch open
Case: Switch close
Exercise | Q 4.2 | Page 111
Write the answer in your word.
Write the properties of a magnet.
SOLUTION
Properties of a magnet are following:
• A magnet has two poles known as North-Pole and South-Pole.
• A magnet, when suspended freely, always rests in north-south direction.
• A magnet has an attractive properties i.e. it always attracts magnetic materials
towards it.
• Like poles of magnets repel each other whereas unlike poles attract each other.
• The two poles of a magnet are inseparable. It means that when a magnet is cut
into two parts, two independent magnets are formed.
• Magnetic force of a magnet is concentrated at its two poles.
Exercise | Q 4.3 | Page 111
Write the answer in your word
What are the practical uses of a magnet?
SOLUTION
Magnets have very wide range of uses:
• Magnetic compass: With the help of a magnetic compass, you can know the
directions at a particular place. The red end of the needle indicates the North
direction.
• Magnets in daily life: Magnets are used in refrigerator doors, as pin holders, in
screwdrivers, etc.
• Magnet in junkyard: In the junkyard, you will see that a large magnet is
attached at the bottom of the arm of a crane. The arm moves over a heap of junk
and the magnet collects objects made of iron. The magnet used in a junkyard
crane is not a natural or a permanent magnet. It is a temporary magnet, which is
called an electromagnet.
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