Human Eye and the Colourful World MCQs Quiz Multiple Choice Questions & Answers

1. A spectrum of light is observed when white light is directed to a prism as

1. the different colours in the white light bend away from the normal line at different angles onentering prism.
2. the different colours in the white light bend towards the normal line at different angles on entering prism.
3. the different colours in the white light bend away from the normal at same speed to each other on entering the prism.
4. the different colours in the white light bend towards the normal at same speed to each other on entering prism.

2. A student is observing the diagram showing the path of a ray of light passing through a glass prism. He would find that for all angles of incidence the ray of light bends:

1. towards the normal while entering into the prism and away from the normal while emerging out of the prism
2. away from the normal while entering into the prism and towards the normal while emerging out of the prism.
3. away from the normal while entering as well as while emerging out of the prism.
4. towards the normal while entering as well as while emerging out of the prism.

3. A student traces the path of a ray through a glass prism for four different values of angle of incidence. On analysing the diagrams he is likely to conclude that the emergent ray

1. is always parallel to the incident ray.
2. is always perpendicular to the incident ray.
3. is always parallel to the refracted ray.
4. always bends at an angle to the direction of incident ray.

4. Apparent position of the star appears raised due to

1. atmospheric refraction
2. scattering of light
3. both a and b
4. none of these

5. At the time of sunrise and sunset

1. Blue colour scattered and red colour reaches our eye
2. Red colour scattered and blue colour reaches our eye
3. Green and blue scattered and orange reaches our eye
4. None of these

6. At the time of sunrise and sunset, the light from sun has to travel

1. longest distance of atmosphere
2. shortest distance of atmosphere
3. both a and b
4. cant say

7. Atomspheric refraction occurs because

1. refractive index in medium is gradually changing
2. of presence of dust particles in atmosphere
3. large amount of moisture is present in atmosphere on a humid day
4. sun rays travel the most when sun is near the horizon

8. Blue colour of the sky is due to the phenomenon of:

1. Reflection of light
2. Refraction of light
3. Dispersion of light
4. Scattering of light

9. Clouds appears white due to

1. Water droplets scatters all wavelength
2. Water in frozen conditions looks icy white
3. Fog is formed around clouds
4. all of these

10. Due to atmospheric refraction, apparent length of the day

1. increases
2. decreases
3. remains the same
4. all of these

11. Fibre optics work on the principle of

1. Scattering of light
2. Total internal reflection
3. Total internal absorption
4. Optical rotation

12. For which of the following cases will the total internal reflection of light be possible?

1. Angle of incidence is less than the critical angle.
2. Angle of incidence is equal to the critical angle.
3. Angle of incidence is greater than the critical angle.
4. Angle of incidence is equal to the angle of refraction.

13. If the angle of incidence of light while leaving the denser object is zero, the light would

1. be reflected back
2. go straight without any refraction
3. be refracted
4. end up at the boundary of the object

14. In absence of atmosphere, the colour of sky appears

1. blue
2. black
3. red
4. yellow

15. Mirage is an example of

1. reflection of light and refraction of light
2. dispersion of light
3. total internal reflection
4. refraction of light and total internal reflection

16. Mirage is formed because:

1. air above the ground is very hot and air above is cooler
2. both a and d are correct
3. light rays from a distant object bend towards the normal when coming towards the ground.
4. light rays from a distant object bend away from the normal when coming towards the ground.

17. Mirages are common in

1. rainforests
2. dry forests
3. deserts
4. highlands

18. Name the scientist who was the first to use a glass prism to obtain the spectrum of sunlight.

1. Isaac Newton
2. Einstein
3. Kepler
4. Hans Christian Oersted

19. One cannot see through the fog, because

1. refractive index of the fog is very high
2. light suffers total reflection at droplets
3. fog absorbs light
4. light is scattered by the droplets

20. Rainbows are created by sunlight

1. water particles
2. wind
3. dust particles
4. snow

21. Reason behind advance sunrise and delayed sunset

1. atmospheric refraction
2. total internal reflection
3. dispersion
4. reflection

22. Refraction of light by the earth's atmosphere due to variation in air density is called

1. atmospheric reflection
2. atmospheric dispersion
3. atmospheric scattering
4. atmospheric refraction

23. Select the colours in the correct ascending of wavelength:

1. blue, green, red
2. orange, green. Red
3. blue, yellow, green
4. orange, yellow, green

24. Sunlight passes through a canopy of a dense forest is due to

1. Raman effect
2. Newton's ring
3. Spectral effect
4. Tyndall effect

25. The air layer of atmosphere whose temperature is less than the hot layer behave as optically

1. denser medium
2. rarer medium
3. inactive medium
4. either denser or rarer medium

26. The blue colour of the sky is because

1. red colour is scattered more as compared to other colours.
2. red colour is absorbed more as compared to other colours
3. blue colour is scattered more as ccompared to other colours
4. blue colour is absorbed more as compared to other colours

27. The bluish colour of water in deep sea is due to

1. the presence of algae and other plants found in water
2. reflection of sky in water
3. scattering of light
4. absorption of light by the sea

28. The clear sky appears blue because

1. blue light gets absorbed in the atmosphere.
2. ultraviolet radiations are absorbed in the atmosphere.
3. violet and blue lights get scattered more than lights of all other colours by the atmosphere.
4. light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.

29. The colour of a star is an indication of its

1. weight
2. distance
3. temperature
4. size

30. The colour of sky appears blue, it is due to the

1. refraction of light through the atmosphere
2. dispersion of light by air molecules
3. scattering of light by air molecules
4. all of these

31. The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light

1. is scattered the most by smoke or fog.
2. is scattered the least by smoke or fog.
3. is absorbed the most by smoke or fog.
4. moves fastest in air.

32. The danger signs made red in colour, because

1. the red light can be seen from farthest distance
2. the scattering of red light is least
3. both a and b
4. none of these

33. The dispersive power of prism depends upon

1. The shape of the prism
2. The material of the prism
3. The angle of the prism
4. Height of the prism

34. The effect of glass prism is only to separate the seven colours of

1. White light
2. light from bulb
3. Sunlight
4. All of the above

35. The phenomena that play a role in the formation of rainbow is:

1. reflection and refraction of light
2. refraction, absorption, dispersion and refraction of light
3. dispersion, refraction and reflection of light
4. Refraction, dispersion, reflection and refraction of light.

36. The phenomenon of scattering of light by the colloidal particles is called

1. Dispersion of light
2. Tyndall effect
3. Atmospheric scattering
4. Atmospheric refraction

37. The refractive index assumes the entrance of light from

1. glass
2. water
3. vacuum
4. gas

38. The splitting of white light into its component colours is called

1. refraction
2. reflation
3. dispersion
4. Tyndall effect

39. The star appear shifted from their actual position due to the phenomenon of

1. Diffraction of light
2. Scattering of light
3. Refraction of light
4. Reflection of light

40. The stars twinkle, while the planets do not. Why?

1. Closer planets are not point sources but due to long distance stars appear as point sources
2. Stars have ability light fragments while planets transmit light continuously
3. Light from star travel faster than planets
4. None of these

41. The sun appears oval shaped or flattened due to

1. dispersion
2. scattering
3. atmospheric refraction
4. cannot say

42. The velocity of waves of all colours is same in:

1. water
2. oxygen
3. vaccum
4. glass

43. To an astronaut in a spaceship, the colour of earth appears

1. red
2. blue
3. white
4. black

44. Twinkling of stars and non-twinkling of planets is accounted for by

1. scattering of light
2. dispersion of light
3. atmospheric refraction
4. none of these

45. Twinkling of stars is due to atmospheric

1. dispersion of light by water droplets
2. refraction of light by different layers of varying refractive indices
3. scattering of light by dust particles
4. internal reflection of light by clouds

46. Tyndall effect is due to

1. scattering of light
2. dispersion of light
3. reflection of light
4. refraction of light

47. What is the colour of the sky when it is seen from moon's surface?

1. Red
2. blue
3. white
4. Black

48. What is the time difference between actual sunset and apparent sunset?

1. 2 sec
2. 20 sec
3. 2 min
4. 20 min

49. What will be the colour of sky if there is no atmosphere on the earth?

1. Dark blue
2. Black
3. white
4. Red

50. When a ray of light travels from an optically denser medium to an optically rarer medium

1. it moves towards the normal
2. it moves away from the normal
3. it is not refracted
4. it is reflected back in the denser medium