CBSE Class 10 Physics: Human Eye and Colourful World – 40 MCQs with Answers

Questions

1. The human eye can focus objects at different distances by changing the focal length of the eye lens. This is due to the ability of the eye called:
   A) Accommodation
   B) Myopia
   C) Presbyopia
   D) Hypermetropia
   
2. The colored part of the eye that controls the amount of light entering is the:
   A) Cornea
   B) Iris
   C) Pupil
   D) Ciliary muscles
   
3. Which part of the eye contains cells that are sensitive to light and converts it into electrical signals?
   A) Retina
   B) Ciliary muscles
   C) Iris
   D) Cornea
   
4. The phenomenon responsible for the twinkling of stars is:
   A) Atmospheric refraction
   B) Total internal reflection
   C) Dispersion of light
   D) Scattering of light
   
5. Myopia is also known as:
   A) Farsightedness
   B) Nearsightedness
   C) Both (A) and (B)
   D) Astigmatism
   
6. A person with myopia can be corrected using a:
   A) Concave lens
   B) Convex lens
   C) Cylindrical lens
   D) Plano-convex lens
   
7. The splitting of white light into its component colors is called:
   A) Reflection
   B) Refraction
   C) Dispersion
   D) Scattering
   
8. Which color of the spectrum has the longest wavelength?
   A) Blue
   B) Green
   C) Violet
   D) Red
   
9. Which color of the spectrum has the shortest wavelength?
   A) Blue
   B) Green
   C) Violet
   D) Red
   
10. The sky appears blue because:
    A) Blue light is absorbed by the atmosphere
    B) Blue light is scattered more than other colors by the atmosphere
    C) The sky reflects blue light from the oceans
    D) The atmosphere emits blue light
    
11. The phenomenon of light scattering by colloidal particles is called:
    A) Tyndall effect
    B) Refraction
    C) Dispersion
    D) Diffraction
    
12. The ability of the eye to see objects clearly at a far distance and near distance is due to:
    A) Myopia
    B) Hypermetropia
    C) Accommodation
    D) Presbyopia
    
13. A person suffering from hypermetropia needs to use a:
    A) Concave lens
    B) Convex lens
    C) Bifocal lens
    D) Cylindrical lens
    
14. The least distance of distinct vision for a young adult with normal vision is about:
    A) 2.5 cm
    B) 25 cm
    C) 25 m
    D) 10 cm
    
15. What is the approximate range of wavelength of visible light?
    A) 100 nm to 200 nm
    B) 400 nm to 700 nm
    C) 700 nm to 1000 nm
    D) 1000 nm to 1500 nm
    
16. The focal length of the eye lens of a person changes while focusing on an object at different distances. This is done by the:
    A) Iris
    B) Pupil
    C) Ciliary muscles
    D) Cornea
    
17. The defect of the eye that is caused by the weakening of ciliary muscles and reduction in the flexibility of the eye lens with aging is called:
    A) Myopia
    B) Hypermetropia
    C) Presbyopia
    D) Astigmatism
    
18. When a person looks at a distant object, the ciliary muscles:
    A) Contract, making the eye lens thicker
    B) Relax, making the eye lens thinner
    C) Contract, making the eye lens thinner
    D) Relax, making the eye lens thicker
    
19. What is the main cause of the formation of a rainbow?
    A) Reflection and refraction
    B) Dispersion and total internal reflection
    C) Diffraction and interference
    D) Scattering and dispersion
    
20. The outermost transparent part of the human eye is the:
    A) Iris
    B) Pupil
    C) Cornea
    D) Retina
    
21. Which part of the eye controls the size of the pupil?
    A) Cornea
    B) Iris
    C) Retina
    D) Ciliary muscles
    
22. When a ray of light enters a glass prism, it bends:
    A) Towards the base of the prism
    B) Away from the base of the prism
    C) Parallel to the base of the prism
    D) It does not bend
    
23. The band of seven colours that is formed on the screen when white light passes through a prism is called:
    A) VIBGYOR
    B) Spectrum
    C) Rainbow
    D) Scattering
    
24. The formation of the rainbow in the sky is an example of:
    A) Refraction and scattering
    B) Total internal reflection and dispersion
    C) Dispersion and refraction
    D) All of the above
    
25. The reddish appearance of the sun at sunrise and sunset is due to:
    A) Refraction of light
    B) Dispersion of light
    C) Scattering of light
    D) Total internal reflection
    
26. Which of the following colors is least scattered by smoke or fog particles?
    A) Blue
    B) Red
    C) Yellow
    D) Green
    
27. The ability of the eye to change its focal length is called:
    A) Accommodation
    B) Reflection
    C) Refraction
    D) Dispersion
    
28. The image formed on the retina of the human eye is:
    A) Real and erect
    B) Virtual and erect
    C) Real and inverted
    D) Virtual and inverted
    
29. The defect of the eye where a person cannot see far-off objects clearly is called:
    A) Myopia
    B) Hypermetropia
    C) Presbyopia
    D) Astigmatism
    
30. The focal length of the eye lens increases when ciliary muscles:
    A) Relax and make the lens thinner
    B) Contract and make the lens thicker
    C) Relax and make the lens thicker
    D) Contract and make the lens thinner
    
31. The lens of the human eye is a:
    A) Convex lens
    B) Concave lens
    C) Plano-convex lens
    D) Plano-concave lens
    
32. The path of light becomes visible when it passes through a colloidal solution. This is because of:
    A) Refraction
    B) Diffraction
    C) Scattering
    D) Reflection
    
33. The human eye has a pair of light-sensitive cells. These are:
    A) Cornea and Iris
    B) Rods and Cones
    C) Lens and Retina
    D) Pupil and Ciliary Muscles
    
34. The amount of light entering the eye is regulated by the:
    A) Ciliary muscles
    B) Pupil
    C) Iris
    D) Retina
    
35. The part of the retina where the optic nerve leaves the eye and there are no photoreceptor cells is called the:
    A) Blind spot
    B) Yellow spot
    C) Pupil
    D) Iris
    
36. Which of the following phenomena is responsible for the blue color of the sky?
    A) Atmospheric reflection
    B) Atmospheric refraction
    C) Scattering of light
    D) Dispersion of light
    
37. A person cannot see near objects clearly but can see distant objects. The person is suffering from:
    A) Myopia
    B) Hypermetropia
    C) Presbyopia
    D) Astigmatism
    
38. The phenomenon of atmospheric refraction is responsible for:
    A) Twinkling of stars
    B) Advanced sunrise
    C) Delayed sunset
    D) All of the above
    
39. The splitting of white light into its constituent colours by a prism is called dispersion. The reason for this is:
    A) Different colors of light have different refractive indices in the prism
    B) The prism absorbs some colours of light
    C) The prism reflects some colours of light
    D) Different colours have the same wavelength
    
40. What is the function of the lens in the human eye?
    A) To control the amount of light entering the eye
    B) To form a real and inverted image of an object on the retina
    C) To provide a pathway for the light
    D) To protect the eye from injury

Answers

1. A) Accommodation
2. B) Iris
3. A) Retina
4. A) Atmospheric refraction
5. B) Nearsightedness
6. A) Concave lens
7. C) Dispersion
8. D) Red
9. C) Violet
10. B) Blue light is scattered more than other colors by the atmosphere
11. A) Tyndall effect
12. C) Accommodation
13. B) Convex lens
14. B) 25 cm
15. B) 400 nm to 700 nm
16. C) Ciliary muscles
17. C) Presbyopia
18. B) Relax, making the eye lens thinner
19. B) Dispersion and total internal reflection
20. C) Cornea
21. B) Iris
22. A) Towards the base of the prism
23. B) Spectrum
24. D) All of the above
25. C) Scattering of light
26. B) Red
27. A) Accommodation
28. C) Real and inverted
29. A) Myopia
30. A) Relax and make the lens thinner
31. A) Convex lens
32. C) Scattering
33. B) Rods and Cones
34. C) Iris
35. A) Blind spot
36. C) Scattering of light
37. B) Hypermetropia
38. D) All of the above
39. A) Different colors of light have different refractive indices in the prism
40. B) To form a real and inverted image of an object on the retina