The DAV Class 6 Science Book Solutions and DAV Class 6 Science Chapter 12 Question Answer – Light and Shadows are essential study tools for DAV public school students in Class 6.
DAV Class 6 Science Ch 12 Question Answer – Light and Shadows
DAV Class 6 Science Ch 12 Solutions – Light and Shadows
Something To Know
A. Fill in the blanks.
Question 1.
An object that allows light to pass through it (almost) completely, is known as a ______ object.
Answer:
Transparent
Question 2.
A shadow is observed on a screen when an ______ object comes in between it and a source of light.
Answer:
Opaque
Question 3.
Shadows formed are always ______ irrespective of the colour of the object.
Answer:
Black
Question 4.
A ______ is a natural phenomenon that sometimes occurs on a new moon day.
Answer:
Solar eclipse
Question 5.
When light is reflected from a plane mirror, it changes its ______ of propagation.
Answer:
Direction
B. Match the following.
| (1) Natural sources of light | (a) Light moves along a straight path |
| (2) CFL, LED and tubelight | (b) Lateral inversion |
| (3) Rectilinear propagation of light | (c) Shadow cast by heavenly body |
| (4) Eclipse | (d) Man-made sources of light |
| (5) Interchange of the ‘left’ and ‘right’ sides in the image | (e) Sun, stars and firefly |
Answer:
| (1) Natural sources of light | e | (a) Light moves along a straight path |
| (2) CFL, LED and tubelight | d | (b) Lateral inversion |
| (3) Rectilinear propagation of light | a | (c) Shadow cast by heavenly body |
| (4) Eclipse | c | (d) Man-made sources of light |
| (5) Interchange of the ‘left’ and ‘right’ sides in the image | b | (e) Sun, stars and firefly |
C. Tick (✓) the correct option.
1. Objects, like the sun, which emit light of their own, are called
(a) Luminous objects
(b) Non-luminous objects
(c) Absorbers of light
(d) Reflectors of light
Answer:
(a) Luminous objects
2. An object, through which we can see partially, but not very clearly, is
(a) A rubber ball
(b) A sheet of tracing paper
(c) A sheet of plane glass
(d) A Compact disk
Answer:
(b) A sheet of tracing paper
3. The ‘something’ which can change its shape and size, and may appear and disappear anywhere/anytime, is known as a
(a) Image
(b) Shadow
(c) Beam of light
(d) Reflector of light
Answer:
(b) Shadow
4. When sun (during early morning) is behind an object, the size of its shadow in comparison to that of the object would be
(a) Smaller
(b) Equal
(c) Larger
(d) Almost zero
Answer:
(c) Larger
5. The image, formed by a pinhole camera, is
(a) Erect and diminished
(b) Inverted and enlarged
(c) Inverted and diminished
(d) Erect and enlarged
Answer:
(c) Inverted and diminished
D. Answer the following questions in brief.
Question 1.
Classify the materials given below as opaque, transparent or translucent. Air, smoke, fog, aluminium sheet, wooden board, cellotape, polythene sheet, lime juice, wax, rubber tyre and milk
Answer:
Opaque: aluminium, wooden board, wax, rubber tyre and milk Transparent: Air, cellotape, polythene sheet Translucent: smoke, lime juice
Question 2.
State the type of path that light ordinarily follows when going from one point to another.
Answer:
Straight line.
Question 3.
Do fishes cast shadows in water?
Answer:
Since water is transparent, it does not act like screen. So, fishes do not cast shadows in water.
Question 4.
On a sunny day, two identical bedsheets, of red an dgreen colour, are hanging on a clothes line. What would be the colour of the shadows of these two bedsheets?
Answer:
Black.
Question 5.
State the relative positions of the sun, moon and the earth, during a lunar eclipse.
Answer:
During a lunar eclipse, the earth is between the sun and the moon.
E. Answer the following questions.
Question 1.
Cover the face of a torch with a transparent coloured paper. Send its beam through an opaque object. What do you observe?
Answer:
In this case, irrespective of the colour of the light beam, the shadow is of black colour.
Question 2.
With the help of suitable diagrams, show that the size of shadow formed, depends upon the relative position of the source and the opaque object.
Answer:
Question 3.
Raghav set up the following arrangement in the science laboratory. He put (i) a steel glass (ii) a transparent glass, at the position P, one by one. Would a shadow be formed in each case? Give reason for your answer.
Answer:
No shadow will be formed in case of transparent glass but a shadow will be formed in case of a steel glass. Steel glass is opaque and hence its shadow is formed.
Question 4.
With the help of a diagram, to show the formation of an image by a pinhole camera.
Answer:
Question 5.
Give the meaning of the term ‘Lateral inversion’. Suggest how it may be used to send a ‘coded (secret)’ message.
Answer:
Interchange of the left and right sides in the image is called lateral inversion. It can be used to send secret messages by using inverted letters in words or by making signals by hands.
Value Based Questions
When Sumiti got admission to her new school, her class teacher advised her to follow the example of her cousin sister, Karmatha, a senior student in the same school. The teacher told her that Karmatha had, all along, been a hard working, sincere, regular, well behaved and disciplined student. She also told her that Karmatha’s nature was unlike that of the shadow of an object. This was because the shadow often changes its size and appearance, with a change in the source of light to which it was due.
Question 1.
Which, according to you, are the two values, displayed by Karmatha, that Sumiti must follow?
Answer:
Dedication to a cause and firmness in one’s resolution.
Question 2.
Does the size of the shadow, of a given object, change even when there is no change in the source of light? Give one example in support of your answer.
Answer:
When there is no change in the source of light, the size of the shadow does not change. This can be seen by the size of the shadow made by a candle which is at a fixed position.
Question 3.
Try to add as many entries, as possible, to the table given below.
| Name of the ‘entry’ | Its cause | Does it change or not? |
| Shadow of an object | Source of light | It often changes its size |
| Directlion of a freely suspended magnet | Earth’s magnetism | Does not change |
Answer:
| Name of the ‘entry’ | Its cause | Does it change or not? |
| Shadow of an object | Source of light | It often changes its size |
| Direction of a freely suspended magnet | Earth’s magnetism | Does not change |
| Shape of water | Shape of container | It often changes |
| Shape of a solid | Shape of container | It does not change |
Something To Do
Question 1.
On a sunny day, go out on to the playground and set up a metre scale (metallic, or wooden) vertically. At different times of the day, go out and measure the length of shadow of the metre scale with another metre scale. Make a bar chart showing the length of the shadow at different times. Can it work as your sundial? Try visiting a place where there is a sundial.
Answer:
Do it yourself.
Hint: Shadow is longer during morning and evening and smaller during noon.
Question 2.
Make shadow puppets. Use your puppets and your imagination, to set up a short play that makes use of the characteristics of light and shadows. If possible, stage the play.
Answer:
Do it yourself.
Question 3.
Transparent objects can also cause shadows. Think it over. Identify such cases, and conditions, for shadow formation.
Answer:
To understand this, take a glass sheet and keep it in sun. Try to locate the faint shadow formed by it.
Question 4.
There is an interesting ‘Pinhole camera’ in nature. Try finding out its details.
Answer:
The canopy of a tree works like a pinhole camera. Try to view the sun through a thick foliage of tree.
DAV Class 6 Science Chapter 12 Solutions – Light and Shadows
I. Fill in the blanks.
Question 1.
Light always travels in a ______ line.
Answer:
Straight
Question 2.
A glass sheet is a ______ material, so it allows complete passage to light.
Answer:
Transparent
Question 3.
A wooden board is a/an ______ material, so it doesn’t allow passage to light.
Answer:
Opaque
Question 4.
______ reflection happens from a plane mirror.
Answer:
Regular
Question 5.
______ reflection happens from a rough surface.
Answer:
Irregular
Question 6.
The shadow of a red ball is of ______ colour.
Answer:
Black
II. Tick ( ✓) the correct option.
1. Which of these is a transparent material?
(a)Water
(b) Soil
(c) Smoke
(d) Cement
Answer:
(a) Water
2. Which of these is a translucent material?
(a) Polythene sheet
(b) Oil
(c) Wax
(d) Tin
Answer:
(b) Oil
3. At which of the times, the shadow of a tree would be the longest?
(a) 6:00 AM
(b) 11:00 AM
(c) 1:00 PM
(d) 3:00 PM
Answer:
(a) 6:00 AM
4. The solar eclipse happens on which of these days?
(a) Full moon day
(b) New moon day
(b) Quarter moon day
(d) Crescent moon day
Answer:
(b) New moon day
5. The lunar eclipse happens on which of these days?
(a) Full moon day
(b) New moon day
(c) Quarter moon day
(d) Crescent moon day
Answer:
(a) Full moon day
III. Answer these questions.
Question 1.
What is light?
Answer:
Light is a source of energy which produces the sensation of sight in our eyes.
Question 2.
What do you understand by a transparent object?
Answer:
An object which allows light to pass through it is called transparent object, e.g. glass sheet, water and some types of plastic.
Question 3.
What do you understand by opaque object?
Answer:
An object which does not allow light to pass through it is called opaque object, e.g. cardboard, wood, metal, etc.
Question 4.
What do you understand by translucent object?
Answer:
An object which allows light to pass through it partially is called translucent object, e.g. butter paper, oil, etc.
Question 5.
What is a shadow?
Answer:
When an opaque object comes in the path of light, a dark region is formed on a screen which is kept behind the object. This dark region or patch is called shadow.
Question 6.
Which are the things necessary for shadow formation?
Answer:
Three things required for the formation of shadow are:
(a) A source of light
(b) An opaque object
(c) A screen (ground/wall) to obtain the shadow.
Question 7.
What are the various characteristics of shadow?
Answer:
Characteristics of Shadow:
(a) The size of the shadow depends on the distance between the source of light and the opaque object.
(b) Shadow of an opaque object is always black; irrespective of the colour of the object.
IV. Projects
Question 1.
Make a model of solar eclipse; by using balls of different sizes. Give a presentation on this in your class.
Answer:
Do it yourself.
Question 2.
Make project report on shadow puppets from Southern India.
Answer:
Do it yourself.