Human Eye and the Colourful World MCQ Quiz - Multiple Choice Questions & Answers Page 5

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