Selina solutions concise physics class 6 icse Solutions for Chapter 5 light

Q1) Write true or false for each statement :

(a)The moon is a natural source of light.

(b) the moon is self-luminous.

(c) we can see an object through an opaque medium.

(d) light passes through glass.

(e) light travels in a straight-line path.

(f) Image formed in a pinhole camera is real.

(g) the image in a pinhole camera gets blurred if the hole is made bigger.

(h) a shadow is formed because light travels in a straight-line path.

(i) solar eclipse occurs when the sun comes in between the earth and the moon.

(j) if the shadows of earth fall on the moon, the eclipse is called the lunar eclipse.

Q2) Fill in the blanks

1. Light gives us the sensation of _____.
2. The sun is a ______ source of light
3. A medium through which light cannot pass is called the ______.
4. A medium which allows light to pass through it easily is called the ________.
5. Moon is a _______ body.
6. Light travels in a ______ path
7. In a pinhole camera, the image formed is ______.
8. The darkest portion of a shadow is called the _____.
9. The less dark portion of a shadow is called the _______.
10. Lunar eclipse occurs when the ____ comes in between the ____ and the sun.

Q3) Match the following :

Q4) Select the correct alternative

(a) The natural source of light is

1. candle flame

2. electric lamp

3. sun

4. kerosene lamp

(b) The formation of an inverted image in a pinhole camera shows that

1. light enables us to see

2. light travels in a straight line path

3. light can pass through the pinhole

4. light does not pass through the pin hole

(c) The luminous body is

1. a light bulb

2. earth

3. noon

4. table

(d) Umbra is a region of

1. complete darkness

2. partial darkness

3. complete brightness

4. partial brightness

(e) Penumbra is a region of

1. complete darkness

2. partial darkness

3. partial brightness

4. none of the above

(f) Solar eclipse occurs on

1. every new moon’s day

2. certain new moon’s day

3. every full moon’s day

4. certain full moon’s day

(g) Lunar eclipse occurs on

1. every full moon’s night

2. certain full moon’s day

3. every new moon’s day

4. certain new moon’s day

Q1) What is light? Define it.

Q2) How does light make an object visible?

Q3) Name two natural sources of light .

Q4) List two artificial sources of light.

Q5) Differentiate between the luminous and non- luminous bodies. Give two examples of each.

Q6) Is the moon a luminous object?

Q7) What do we call a body that shines on its own?

Q8) What do we call an electric bulb producing light?

Q9) What is a transparent medium? Give two examples.

Q10) Explain the difference between a transparent, translucent and an opaque medium. Give two examples of each.

Q11) What do we call a substance through which we cannot see light? give an example of such a substance.

Q12) What do we call a substance through which light passes? Give an example of such a substance.

Q13) Can a transparent medium form an image? Explain your answer.

Q14) How can you obtain a point source of light?

Q15) Define the terms: a ray of light and a beam of light.

Q16) What do you mean by ‘ rectilinear propagation of light’?

Q17) Describe an experiment to show that light travels in a straight line path.

Q18) In which of the following two arrangements (a) and (b) shown in the diagram, you can see the light of the bulb? explain your answer

Q19) Name a simple application of the rectilinear propagation of light.

Q20) What is a pinhole camera? Draw a neat and labelled diagram to show the formation of an image of a lighted candle by it.

Q21) Explain the formation of an image of a luminous object in a pinhole camera with the aid of a neat diagram.

Q22) State two factors which affect the size of the image formed in a pinhole camera.

Q23) Is the image obtained in a pinhole camera erect or inverted? Give reason for your answer.

Q24) How is the image affected in a pinhole camera when another fine hole is made near the first pinhole?

Q25) State the effect on the image in a pinhole camera if

1. The hole is made bigger
2. The luminous object is moved towards the pinhole
3. The length of the pinhole camera has increased.

Q26) What is a shadow? Give a reason for its formation.

Q27) Draw a ray diagram to show the formation of the shadow of an opaque object by a point source of light. How is the size of shadow affected if the screen is moved away from the object?

Q28) State two differences between an umbra and a penumbra.

Q29) Draw a ray diagram to show the formation of umbra alone

Q30) Draw a ray diagram to show the formation of umbra and penumbra both. Label the parts umbra and penumbra in your diagram.

Q31) In each of the following diagrams, draw rays to form umbra and penumbra on the screen.

Q32) State the conditions when only the penumbra of an opaque object is obtained on the screen.

Q33) Why is it that the birds flying in the sky do not cast their shadow on the earth.

Q34) Why are shadows at noon shorter than in the morning or in the evening?

Q35) What is an eclipse? Name the two types of eclipses.

Q36) When does a lunar eclipse take place? Does it occur on every full moon’s night?

Q37) Draw a diagram to show the formation of the lunar eclipse?

Q38) When does a solar eclipse take place? Does it occur on even a new moon’s day?

Q39) Draw a diagram to show the formation of the solar eclipse?

Q40) What is an annular solar eclipse? draw a labelled diagram to show its formation.