Olympiad Science - Light, Shadows and Reflections
Exam Duration: 45 Mins Total Questions : 30
Identify translucent objects given in the box.
(i) Ground glass
(ii) Ice
(iii) Wood
- (a)
Only (i) and (ii)
- (b)
Only (ii) and (iii)
- (c)
Only (i) and (iii)
- (d)
All the above
Which of the following emits light?
- (a)
A book
- (b)
A glow worm
- (c)
A bat
- (d)
A rat
Why does an opaque object form a shadow when placed in the path of light?
- (a)
Because light gets reflected
- (b)
Because the opaque object does not allow light to pass through it
- (c)
Because the opaque object acts as a source of light
- (d)
Because light is a form of energy
Which of the following reflects light the most?
- (a)
A mirror
- (b)
A piece of paper
- (c)
A cloth
- (d)
A wooden table
What happens when light falls on a wooden chair?
- (a)
A part of the light reflected from the chair enters our eyes.
- (b)
Light passes through the wooden chair.
- (c)
The chair sends a signal to our eyes that enable us to see it.
- (d)
Electrical energy is given out by the chair.
Which of the following materials can transmit most of the light?
- (a)
A glass block
- (b)
A piece of blank paper
- (c)
A spot of black ink
- (d)
A placid lake surface
In the morning, when the sun rises in the east. your shadow will be seen on the
- (a)
east
- (b)
North
- (c)
West
- (d)
south
Observe the figure given below.
Identify X, Y and Z
- (a)
X Y Z Opaque Light source Shadow - (b)
X Y Z Light source Opaque body Light source - (c)
X Y Z Light source Opaque body Shadow - (d)
X Y Z Opaque body Shadow Light source
Which of the following statements about shadows is incorrect
- (a)
The shadow of an object is formed on the opposite side of the light source
- (b)
The position of the shadow changes with the position of the light source.
- (c)
The position of the shadow changes with the movement of the object
- (d)
A transparent body produces a shadow
You cannot see the flame of a burning candle by looking through a bent pipe. This is because
- (a)
light gets bent along the pipe
- (b)
light travels in a straight line.
- (c)
light gets reflected
- (d)
light gets absorbed
At what time will the shadow cast by a pole under the sun be the shortest?
- (a)
8.30 a.m.
- (b)
10.00 a.m.
- (c)
12 noon
- (d)
5.00 p.m.
The moon is a non-luminous object but still it is visible to us. Why?
- (a)
The moonlight travels only in the form of rays
- (b)
The moon reflects the light falling on it from the sun
- (c)
The moonlight emits visible light.
- (d)
The moonlight travels in curved paths.
The diagram given below shows the positions of four students P, Q, R and S observing the flame of a candle through the pipes
Which student can see the candle flame?
- (a)
P
- (b)
Q
- (c)
R
- (d)
S
We cannot see an object when
(i) it reflects light.
(ii) it casts a shadow.
(iii) there is no light
- (a)
Only (i)
- (b)
Only (ii)
- (c)
Only (iii)
- (d)
All the above
Which of the following is grouped incorrectly?
- (a)
Luminous bodies Non-luminous bodies Firefly Housefly - (b)
Luminous bodies Non-luminous bodies Glow-worm Earthworm - (c)
Luminous bodies Non-Luminous bodies Metal spoon Torchlight - (d)
Luminous bodies Non-Luminous bodies Star Moon
Rahul places a candle in front of three cardboards each with a hole on them and observes on the other side.
What inference does he make from the given experiment?
- (a)
Light rays are very thin.
- (b)
Light rays travel in straight lines.
- (c)
The eye can only see a luminous body.
- (d)
A beam of light is made up of a lot of light rays
The length of the shadow of a tree will keep changing with respect to
- (a)
the sun.
- (b)
a lamp
- (c)
a distant star
- (d)
a torch.
A girl given in the figure is able to see the dog.
Which one of the following is the reason?
- (a)
Light falls on the dog
- (b)
Light gets reflected from the dog into the girl's eyes.
- (c)
It is dark
- (d)
Light from the bulb reaches the girl's eyes.
Which of these is a non-luminous object?
- (a)
Sun
- (b)
Stars
- (c)
moon
- (d)
firefly
Study the table given below and answer questions 2 to 5.
P | Q | R |
Air | Frosted glass | Paper |
Water | Waxed paper | Wood |
Oxygen | Coloured polythene sheet | Telephone cable |
Glass | Butter paper | Wall |
Polythene sheet | S | Iron |
'P' column has
- (a)
all opaque objects.
- (b)
a mix of opaque and transparent objects.
- (c)
all luminous objects.
- (d)
all transparent objects.
Study the table given below and answer questions 2 to 5.
P | Q | R |
Air | Frosted glass | Paper |
Water | Waxed paper | Wood |
Oxygen | Coloured polythene sheet | Telephone cable |
Glass | Butter paper | Wall |
Polythene sheet | S | Iron |
'R' can also have
- (a)
marble.
- (b)
granite.
- (c)
sandstone.
- (d)
all of these.
Study the table given below and answer questions 2 to 5.
P | Q | R |
Air | Frosted glass | Paper |
Water | Waxed paper | Wood |
Oxygen | Coloured polythene sheet | Telephone cable |
Glass | Butter paper | Wall |
Polythene sheet | S | Iron |
The objects listed under 'Q' are special because
- (a)
we can see through them partially.
- (b)
light can pass through them only partially.
- (c)
they are translucent.
- (d)
all of these.
Which one of these is not a man-made luminous object?
- (a)
lighted tube light
- (b)
lighted bulb
- (c)
burning candle
- (d)
none of these
Which one of these is a cold source of light?
- (a)
burning kerosene lamp
- (b)
burning candle
- (c)
lighted electric bulb
- (d)
glow-worm
Keep a lighted candle on a table in a dark room. Look at the lighted candle through a drinking straw. If the straw is bent will the light be visible through it?
- (a)
yes
- (b)
partially
- (c)
no
- (d)
none of these
A weak shadow is formed if the object is_____________.
- (a)
translucent
- (b)
opaque
- (c)
transparent
- (d)
all of these
Choose the statement that is true.
- (a)
The length of our shadow can change depending on our position with respect to the source of light.
- (b)
The length of our image in a plane mirror will be same as our length.
- (c)
The image in a plane mirror is as coloured as the object in front of it.
- (d)
all of these.
When we walk down a well-lit road at night we can see
- (a)
our Image
- (b)
our shadow
- (c)
our reflection
- (d)
all of these
Choose the correct statement.
- (a)
Regular reflection is produced by a smooth and well-polished surface.
- (b)
Diffused or irregular reflection is produced by ordinary surfaces.
- (c)
There is an interchange of right and left between the object and its image in a plane mirror.
- (d)
All of these.
Find the incorrect statement.
- (a)
The colour of shadow does not change with the change in the colour of the light.
- (b)
The colour of shadow does not change with the change in the colour of the object placed in the path of the light.
- (c)
The shadow formed is always black in colour.
- (d)
none of these