Human Eye and the Colourful World MCQ Questions and Answers for Practice

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