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CLASS VI T3 Science Magnetism Book back Questions and Answers
Unit 1
Magnetism
Evaluation
I. Choose the appropriate answer
1. An object that is attracted by magnet.
a. wooden piece
b. plain pins
c. eraser
d. a piece of paper
Ans: b. plain pins
2. People who made mariner’s compass for the first time.
a. Indians
b. Europeans
c. Chinese
d. Egyptians
Ans: c. Chinese
3. A freely suspended magnet always comes to rest in the _____________
direction
a. North - east
b. South - west
c. East - west
d. North - south
Ans: d. North - south
4. Magnets lose their properties when they are___________.
a. Used
b. stored
c. hit with a hammer
d. Cleaned
Ans: c. hit with a hammer
5. Mariner’s compass is used to find the _____________.
a. speed
b. displacement
c. direction
d. Motion.
Ans: c. direction
II. Fill in the Blanks
1. Artificial magnets are made in different shapes such as __________,
__________ and ____________.
Ans: Oval, cylindrical and horse shoe
2. The Materials which are attracted towards the magnet are Called________.
Ans: magnetic substances
3. Paper is not a ______ material.
Ans: magnetic
4. In olden days, sailors used to find direction by suspending a piece of
___________.
Ans: leading stones or lode stones
5. A magnet always has __________ poles.
Ans: two
III. True or False. If False, give the correct statement
1. A cylindrical magnet has only one pole.
Ans: False
A cylindrical magnet has two poles.
2. Similar poles of a magnet repel each other.
Ans: True
3. Maximum iron filings stick in the middle of a bar magnet when it is brought near them.
Ans: False
Maximum iron filings stick in the poles of a bar magnet when it is brought near them.
4. A compass can be used to find EastWest direction at any place.
Ans: True.
With the help of a compass, one can find all the directions. In general, a freely suspended magnet always shows north-south direction. Based on this, we can find the rest of the directions.
5. Rubber is a magnetic material.
Ans: False
Rubber is a non-magnetic material.
IV. Match the following
V. Circle the odd ones and give reasons
1. Iron nail, pins, rubber tube , needle.
Ans: rubber tube
Rubber is a non-magnetic substance, all other materials are magnetic substances.
2. Lift, escalator, electromagnetic train, electric bulb.
Ans: Electric bulb
Electric bulbs do not have electromagnetic properties, but others work under the principle of electromagnetism.
3. Attraction, repulsion, pointing direction, illumination.
Ans: Illumination
Illumination is not the property of magnet, all others are the property of magnet.
VI. The following diagrams show two magnets near one another. Use the words,
'Attract, Repel, Turn around' to describe what happens in each case.
Ans:
a. Unlike poles ATTRACT each other
b. Like poles REPEL each other
c. Unlike poles ATTRACT each other
d. Perpendicular poles TURN AROUND and attract one another
e. Like poles attract each other
f. Perpendicular poles TURN AROUND and attract one another
VII. Write down the names of substances.
VIII. Give short answer
1. Explain the attraction and repulsion between magnetic poles.
The attractive force of the magnet is very large near the two ends. These two ends are called its poles.
Unlike poles (S-N, N-S) attract each other.
Like Poles (N-N, S-S) repel each other.
2. A student who checked some magnets in the school laboratory found out that their magnetic force is worn out. Give three reasons for that?
Magnets lose their properties if they are:
heated
dropped from a height
hit with a hammer
IX. Answer in detail
1. You are provided with an iron needle. How will you magnetize it ?
I took an Iron needle and placed it on a table.
Next, I have taken a bar magnet and placed one of its poles near one edge of the Iron needle and rubbed it from one end to another end without changing the direction of the pole of the magnet.
I have repeated the process for 30 to 40 times.
When I brought a pin or some iron filings near the Iron needle it attracted the pins.
So it is clear that the iron needle is now magnetized and becomes a magnet.
2. How does the electromagnetic train work?
Electromagnets are used in Electromagnetic trains.
Electromagnets are magnetized only when current flows through them. When the direction of current is changed, the poles of the electromagnets are also changed.
Like poles of the magnets which are attached at the bottom of the train and track repel each other.
So, the train is lifted from the track up to a height of 10 cm.
We know that we can move any magnetic object with the force of attraction or repulsion properties of magnets.
Electric trains also move with the help of the magnets attached on the sides of track and the magnets fitted at the bottom side of the train.
By controlling the current, we can control the magnets and movement of the train.
X. Questions based on Higher Order Thinking Skills
1. You are provided with iron filings and a bar magnet without labelling the poles of the magnet. Using this...
a. How will you identify the poles of the magnet?
By setting the magnet near the compass, we can easily find the North and South Pole.
Another way to find the pole is, hanging the magnet using thread, it automatically turns itself pointing directly north and the other directly south, which is why we call them the “north” and “south” poles.
b. Which part of the bar magnet attracts more iron filings? Why?
A bar magnet attracts more iron filings near its poles because the intensity of magnetic attraction is stronger near the poles.
2. Two bar magnets are given in the figure A and B. By the property of
attraction,identify the North pole and the South pole in the bar magnet (B)
The Fig -A has S and N poles.
Fig -B shows attraction towards Fig-A.
As only the opposite poles attract each other and the pole near to Fig-B shows N, then the Fig-B nearer to Fig-A will be S.
Fig.B will have S-N poles.
3. Take a glass of water with a few pins inside. How will you take out the pins without dipping your hands into water?
By keeping a magnet on the side of the glass as shown in the figure will attract pins, and by moving magnet towards the tip of the glass the pins can be taken out without dipping the hands in the water.
Or
By placing a strong magnet above the glass of water may attract the pins inside the glass
