PSEB Class 6 Science Chapter 11 Light, Shadows, and Reflections Questions and Answers Solution
PSEB Punjab Board Class 6 Science Textbook Solution Chapter 11 Light, Shadows, and Reflections Exercise Questions and Answers. We have also included some Additional questions, so that students can prepare more strongly.
(1) Fill in the blanks: –
(a) An object that allow light to pass through them partially are known as translucent object.
(b) Light source like the sun that emit light of their own are called luminousobjects.
(c) Never ever look directly at the Sun because it could be extremely harmful for the eyes.
(d) The change in direction of propagation of light when light allowed to fall on polished surface is calledreflect of light.
(e) Due to irregular reflection phenomenon rooms are lighted up in day time though no directsunlight enters the room.
(2) Write True or False: –
(a) Moon is a luminous object.
→False
(b) We can clearly see through transparent material.
→True
(c) Shadow of opaque object is always black.
→ True
(d) Light does not travel in straight line path.
→ False
(e) Due to reflection of light, rooms are lighted up during day time through no direct sunlight enters the room.
→ True
(3) Match the following: –
| 1. | Natural source of light | Sun, stars, and firefly |
| 2. | CFL, LED, and tube light | Man-made sources of light |
| 3. | Rectilinear propagation of light | Light moves along a straight path |
| 4. | Eclipse | Shadow cast by a heavenly body |
| 5. | Cardboard, wood, and metal | Opaque object |
(4) Choose the correct answer: –
(i) Objects, like moon, which do not emit light of their own, are called.
(a) luminous objects
(b) non-luminous objects
(c) absorbers of light
(d) reflectors of light
→ (b) non-luminous objects
(ii) An object, through which we can see partially, but not very clearly, is
(a) A rubber balls
(b) A sheet of plane glass
(c) A sheet of tracing paper
(d) A compact disk
→ (c) A sheet of tracing paper
(iii) When sun (during evening) is behind an object, the size of its shadow in comparison to that of the object would be
(a) Smaller
(b) Almost zero
(c) Larger
(d) Equal
→ (c) Larger
(iv) The image, formed by a pinhole camara, is
(a) Inverted and diminished
(b) Inverted and enlarged
(c) Erect and enlarged
(d) Erect and diminished
→(a) Inverted and diminished
(v) For shadow formation, we require :
(a) An opaque object
(b) A source of light
(c) The screen to obtain the shadow
(d) All of the above
→(d) All of the above
(5) Very short answer questions: –
(i) State the type of path that light ordinarily follows while going from one point to another?
→We know light travels in a straight line.Because of this light follows the shortest path between one point to another. Where the interruption in the path of light is the last point.
(ii) Fishes do not cast shadow in water. Why?
→For shadow formation, we require three things : a source of light, an opaque object, and the screen to obtain the shadow. In water the screen is not available, so we do not see fishes’ shadow.
(iii) State the relative position of sun, earth, and the moon during solar eclipse?
→In solar eclipse, sun is the source of light, moon is the opaque object and the earth is the screen of shadow. Sun – moon – earth in a straight line.
(iv) In a completely dark room. If you hold a mirror in front of you, will you see a reflection of yourself in the mirror?
→ In a completely dark room, if you hold mirror in front of you, we cannot see a reflection of yourself in the mirror. Because there is no presence of light. We can see the objects only in the presence of light.
(v) Two identical bed sheets, of pink and grey colour are hanging on a rope under the sun. What would be the colour of shadow of these two bed sheets?
→Shadow of opaque object is always black irrespective of colour of opaque object.
(6) Short answer questions: –
(i) What is regular reflection?
→When light is allowed to fall on polished or shining surfaces like plane mirror or shining metal sheet, these surfaces reflect light in a well-defined regular manner. Such reflection is known as regular reflection.
(ii) Why shadow in afternoon is smaller than shadow formed in the morning?
→The size of shadow of opaque object depends on relative position of source of light and the opaque objects. So, the shadow in afternoon is smaller than shadow formed in the morning.
Extra Questions and Answers
- Short answer type questions: –
(1) How many sources of ‘Light?’
→There are two sources of light, (1) Natural sources of light, (2) Artificial sources of light. Sun, Stars, etc. are natural sources and Tube light, bulb, CFL, LED, candles are artificial sources.
(2) What is the difference between luminous object and non-luminous objects?
→Which light source give out or emit light of their own are called luminous objects. i.e. sun, candle, CFL, etc. other than, which object do not emit light their own, are called non-luminous objects. i.e. moon, earth, Uranus etc.
(3) State Transparent, Translucent, and opaque objects?
→Transparent : The object , that allow light to pass through them are known transparent objects. i.e. plain glass sheet, clear water, air, etc.
Translucent : The object, that allow light to pass through them partially are known translucent objects. i.e. trace paper, frosted glass, thin cloth etc.
Opaque : The object, that does not allow light to pass through them are known opaque objects. i.e. metal sheet, wall, cardboard, wood items etc.
(4) Give an example where light pass straight-line?
→If we get 3,4-fit of a piece of straight-linemetal pipe and watch towards sun
(with-safety goggles) we can able to show sun very easily. Other than when we use a bend pipe we can not see sun or sunlight. Because the light rays coming towards our eye through pipe is stopped due to bend. Bend is opaque object.
(5) Classify the object given in following table as transparent, translucent, opaque?
|
Object/ material |
Transparent, opaque, Translucent |
| Thin cloth |
Translucent |
|
Bricks plaster wall |
Opaque |
| Clear water |
Transparent |
|
Wooden frame |
Opaque |
| Frosted glass |
Translucent |
|
Plain glass sheet |
Transparent |
(6) Define ‘Shadow’ in short?
→When we hold an opaque object in the front of sunlight or light, slightly above the ground, wall, or screen we saw a dark patch or region is formed whose shape is like opaque object. This dark patch is called ‘shadow.’
(7) Which things are required to formation of shadow?
→ For shadow formation, we require three things:
(1) A source of light,
(2) An opaque object,
(3) The Screen or wall.
(8) Explain Solar Eclipse position?
→At the time of solar eclipse position, source of light is sun, opaque object is moon, and the screen object is earth. i.e. sun-moon-earth.
(9) Explain Lunar Eclipse position?
→ At the time of lunar eclipse position, source of light is sun, opaque object is Earth, and the screen object is moon. i.e. sun-earth-moon.
(10)What is reflection?
→ Reflection means when light bounces off an object, i.e. mirror, polished tiles, steel metal, water, etc. the light will be reflected at the same angle as it hit the surface.