Goa Board Class 6 Solutions for Science – Fun with Magnets (English Medium)
Page No. 134:
Question 1:
Fill in the blanks in the following
(i) Artificial magnets are made in different shapes such as __________, __________ and ___________.
(ii) The materials which are attracted towards a magnet are called________.
(iii) Paper is not a ______ material.
(iv) In olden days, sailors used to find direction by suspending a piece of ___________.
(v) A magnet always has __________ poles.
Solution:
(i) Bar magnets, cylindrical magnets, U-shaped magnets
(ii) Magnetic materials
Concept insight: Only magnetic materials get attracted towards magnets.
(iii) Magnetic
Concept insight: Paper does not get attracted to a magnet so it is not a magnetic material.
(iv) Magnet
Concept insight: A freely suspended magnet always aligns in north- south direction.
(v) Two
Question 2:
State whether the following statements are true or false:
(i) A cylindrical magnet has only one pole.
(ii) Artificial magnets were discovered in Greece.
(iii) Similar poles of a magnet repel each other.
(iv) Maximum iron filings stick in the middle of a bar magnet when it is brought near them.
(v) Bar magnets always point towards North-South direction.
(vi) A compass can be used to find East-West direction at any place.
(vii) Rubber is a magnetic material.
Solution:
(i) False
Concept insight: A magnet of any shape always has two poles.
(ii) False
Concept insight: Natural magnets were discovered in Greece.
(iii) True
Concept insight: Like poles repel each other and unlike poles attract each other.
(iv) False
Concept insight: Maximum number of iron fillings stick on the poles because the pull of a bar magnet is strongest at the poles.
(v) True
Concept insight: A freely suspended magnet always aligns itself in North-South direction.
(vi) True
Concept insight: The needle of a compass points towards the North-South direction. If the North-South direction is known, then East-West direction can also be determined. This direction is perpendicular to the North-South direction i.e., perpendicular to the compass needle in the same plane.
(vi) False
Concept insight: Rubber does not get attracted towards a magnet, so it is a non-magnetic material.
Question 3:
It was observed that a pencil sharpener gets attracted by both the poles of a magnet although its body is made of plastic. Name a material that might have been used to make some part of it.
Solution:
The pencil sharpener gets attracted towards the magnet because it contains a blade made of iron which is a magnetic substance.
Question 4:
Column I shows different positions in which one pole of a magnet is placed near that of the other. Column II indicates the resulting action between them for each situation. Fill in the blanks.
Column I | Column II |
N – N | _________ |
N – _______ | Attraction |
S – N | _________ |
________ – S | Repulsion |
Solution:
Column I | Column II |
N – N | Repulsion |
N – S | Attraction |
S – N | Attraction |
S – S | Repulsion |
Question 5:
Write any two properties of a magnet.
Solution:
Two properties of a magnet are:
1) Each magnet has two magnetic poles – North and South.
2) A freely suspended magnet always aligns in North-South direction.
Question 6:
Where are poles of a bar magnet located?
Solution:
Poles of a bar magnet are located at its two ends.
Question 7:
A bar magnet has no markings to indicate its poles. How would you find out near which end is its North pole located?
Solution:
A freely suspended bar magnet always comes to rest in the North-South direction. The North facing end of the magnet is its North pole, and the South facing end is its South pole (as shown in the figure).
Thus, the unknown poles of a bar magnet can be marked by suspending it freely by a string.
Question 8:
You are given an iron strip. How will you make it into a magnet?
Solution:
Take an iron strip and keep one end of a bar magnet at one end of the iron strip. Without lifting the bar magnet, move it along the length of the iron strip till you reach the other end of the strip. Now lift the bar magnet and bring its same end again at the initial point. Move the bar magnet again along the whole length of iron strip in the same direction as done before. Repeat this process about 30 to 40 times. Then remove the bar magnet and bring some iron filings near the iron strip and check if it is converted to a magnet or not.
Question 9:
How is a compass used to find directions?
Solution:
A compass consists of a magnetic needle with a dial marked with directions. The needle of the compass always comes to rest along the North-South direction. The compass is then rotated until painted end (North pole) of the needle is towards N (North) mark on the dial and the other end of needle is towards S (South) mark on the dial. We can now find any direction by looking at the dial of the compass.
Question 10:
A magnet was brought from different directions towards a toy boat that has-been floating in water in a tub. Affect observed in each case is stated in Column I. Possible reasons for the observed affects are mentioned in Column II. Match the statements given in Column I with those in Column II.
Column I | Column II |
Boat gets attracted towards the magnet. |
Boat is fitted with a magnet with North pole towards its head.
|
Boat is not affected by the magnet.
|
Boat is fitted with a magnet with South pole towards its head. |
Boat moves towards the magnet if North pole of the magnet is brought near its head.
|
Boat has a small magnet fixed along its length.
|
Boat moves away from the magnet when North pole is brought near its head. |
Boat is made of magnetic material.
|
Boat floats without changing its direction. | Boat is made up of non-magnetic material. |
Solution:
Column I | Column II |
Boat gets attracted towards the magnet. |
Boat is made of magnetic material.
|
Boat is not affected by the magnet.
|
Boat is made up of non-magnetic material. |
Boat moves towards the magnet if North pole of the magnet is brought near its head. |
Boat is fitted with a magnet with South pole towards its head.
|
Boat moves away from the magnet when North pole is brought near its head. | Boat is fitted with a magnet with North pole towards its head. |
Boat floats without changing its direction. | Boat has a small magnet fixed along its length. |
Concept insight:
Magnetic materials get attracted towards a magnet.
Non-magnetic materials do not get attracted towards a magnet.
Unlike poles attract each other.
Like poles repel each other.
A freely floating magnet always aligns itself in the North-South direction.