Class 10 Science Chapter 10 The Human Eye and The Colourful World

1. What is the primary function of the human eye’s lens?

(A) To adjust the amount of light entering the eye

(B) To form an image on the retina

(D) To protect the eyeball

Answer

Answer: (B) To form an image on the retina

2. Which part of the eye regulates the amount of light entering it?

(A) Retina

(B) Cornea

(D) Optic nerve

Answer

Answer: (C) Iris

3. What is the shape of the human eyeball?

(A) Cuboidal

(B) Spherical

(D) Elliptical

Answer

Answer: (B) Spherical

4. Which part of the eye is responsible for sending visual signals to the brain?

(A) Pupil

(B) Cornea

(D) Iris

Answer

Answer: (C) Optic nerve

5. What is the minimum distance at which the human eye can see objects clearly without strain?

(A) 10 cm

(B) 25 cm

(D) 100 cm

Answer

Answer: (B) 25 cm

6. What is the ability of the eye to adjust its focal length called?

(A) Refraction

(B) Power of Accommodation

(D) Scattering

Answer

Answer: (B) Power of Accommodation

7. Which part of the eye controls the size of the pupil?

(A) Lens

(B) Retina

(D) Optic nerve

Answer

Answer: (C) Iris

8. What happens when the ciliary muscles relax?

(A) The lens becomes thicker

(B) The lens becomes thinner

(D) The retina contracts

Answer

Answer: (B) The lens becomes thinner

9. What is the near point of a normal human eye?

(A) 10 cm

(B) 25 cm

(D) 100 cm

Answer

Answer: (B) 25 cm

10. What is the condition called when the eye lens becomes cloudy with age?

(A) Myopia

(B) Hypermetropia

(D) Astigmatism

Answer

Answer: (C) Cataract

11. What is Myopia commonly known as?

(A) Farsightedness

(B) Near-sightedness

(D) Presbyopia

Answer

Answer: (B) Near-sightedness

12. Which type of lens is used to correct Myopia?

(A) Convex lens

(B) Cylindrical lens

(D) Bifocal lens

Answer

Answer: (C) Concave lens

13. What is the primary cause of Hypermetropia?

(A) Elongation of the eyeball

(B) Excessive curvature of the lens

(D) Shorter eyeball size

Answer

Answer: (D) Shorter eyeball size

14. Which defect of vision is commonly found in older people?

(A) Myopia

(B) Hypermetropia

(D) Cataract

Answer

Answer: (C) Presbyopia

15. Which type of lens is used to correct Hypermetropia?

(A) Concave lens

(B) Cylindrical lens

(D) Prism lens

Answer

Answer: (C) Convex lens

16. What is the primary cause of Myopia?

(A) Shortening of the eyeball

(B) Elongation of the eyeball

(D) Clouding of the lens

Answer

Answer: (B) Elongation of the eyeball

17. Which of the following conditions occurs when the eye lens loses its flexibility with age?

(A) Myopia

(B) Hypermetropia

(D) Astigmatism

Answer

Answer: (C) Presbyopia

18. What type of lens is used in bifocal glasses for Presbyopia?

(A) Only concave lens

(B) Only convex lens

(D) Cylindrical lens

Answer

Answer: (C) Both convex and concave lenses

19. Which medical procedure can restore vision loss due to cataract?

(A) Laser therapy

(B) Cataract surgery

(D) Medication

Answer

Answer: (B) Cataract surgery

20. What is the far point of a normal human eye?

(A) 10 meters

(B) 25 cm

(D) 1 meter

Answer

Answer: (C) Infinity

21. What is the main function of the pupil in the human eye?

(A) To form an image on the retina

(B) To control the amount of light entering the eye

(D) To detect colors

Answer

Answer: (B) To control the amount of light entering the eye

22. Which part of the eye is responsible for converting light into electrical signals?

(A) Cornea

(B) Optic nerve

(D) Iris

Answer

Answer: (C) Retina

23. Which eye defect is corrected using cylindrical lenses?

(A) Myopia

(B) Hypermetropia

(D) Presbyopia

Answer

Answer: (C) Astigmatism

24. Which of the following is NOT a common defect of vision?

(A) Myopia

(B) Hypermetropia

(D) Cataract

Answer

Answer: (D) Cataract

25. Why do people with Hypermetropia have difficulty seeing nearby objects?

(A) Their eyeball is too long

(B) The image forms behind the retina

(D) The pupil does not contract properly

Answer

Answer: (B) The image forms behind the retina

26. Which eye defect is characterized by difficulty in seeing distant objects clearly?

(A) Myopia

(B) Hypermetropia

(D) Astigmatism

Answer

Answer: (A) Myopia

27. What type of lens is used to correct Hypermetropia?

(A) Concave lens

(B) Convex lens

(D) Bifocal lens

Answer

Answer: (B) Convex lens

28. Which of the following is a common reason for the development of Presbyopia?

(A) Weakening of ciliary muscles

(B) Elongation of the eyeball

(D) Excessive exposure to bright light

Answer

Answer: (A) Weakening of ciliary muscles

29. What is the condition in which a person requires bifocal lenses to see both near and distant objects clearly?

(A) Myopia

(B) Hypermetropia

(D) Presbyopia

Answer

Answer: (D) Presbyopia

30. Which part of the eye is primarily responsible for adjusting the focal length of the lens?

(A) Retina

(B) Cornea

(D) Optic nerve

Answer

Answer: (C) Ciliary muscles

31. What is the primary cause of Myopia?

(A) The eyeball becomes too short

(B) The focal length of the eye lens is too long

(D) The cornea loses transparency

Answer

Answer: (C) The eyeball elongates

32. Which condition occurs when the image of a distant object forms in front of the retina?

(A) Hypermetropia

(B) Presbyopia

(D) Myopia

Answer

Answer: (D) Myopia

33. How is Presbyopia different from Myopia and Hypermetropia?

(A) It occurs due to aging

(B) It is caused by an elongated eyeball

(D) It only affects distant vision

Answer

Answer: (A) It occurs due to aging

34. Which type of lens is commonly used to correct Presbyopia?

(A) Concave lens

(B) Convex lens

(D) Cylindrical lens

Answer

Answer: (C) Bifocal lens

35. Which of the following vision defects can be corrected using a concave lens?

(A) Myopia

(B) Hypermetropia

(D) Cataract

Answer

Answer: (A) Myopia

36. Which eye defect is caused by the weakening of ciliary muscles due to aging?

(A) Myopia

(B) Hypermetropia

(D) Astigmatism

Answer

Answer: (C) Presbyopia

37. Which type of lens is used in spectacles for people suffering from both Myopia and Hypermetropia?

(A) Concave lens

(B) Convex lens

(D) Cylindrical lens

Answer

Answer: (C) Bifocal lens

38. What is the primary function of the retina in the human eye?

(A) To focus light onto the lens

(B) To control the amount of light entering

(D) To regulate eye pressure

Answer

Answer: (C) To convert light into electrical signals

39. Which condition causes a person to have difficulty seeing both near and distant objects clearly?

(A) Myopia

(B) Hypermetropia

(D) Cataract

Answer

Answer: (C) Presbyopia

40. Which vision defect can be corrected using converging lenses?

(A) Myopia

(B) Hypermetropia

(D) Cataract

Answer

Answer: (B) Hypermetropia

41. Which phenomenon is responsible for the twinkling of stars?

(A) Reflection

(B) Dispersion

(D) Atmospheric refraction

Answer

Answer: (D) Atmospheric refraction

42. Why do planets not twinkle like stars?

(A) Planets do not emit their own light

(B) Planets are closer and appear as extended sources

(D) Planets have their own stable light source

Answer

Answer: (B) Planets are closer and appear as extended sources

43. Why does the Sun appear red at sunrise and sunset?

(A) Due to the scattering of shorter wavelengths of light

(B) Because of the reflection from clouds

(D) Due to absorption of blue light by the Sun

Answer

Answer: (A) Due to the scattering of shorter wavelengths of light

44. What causes the apparent flattening of the Sun’s disc at sunrise and sunset?

(A) Reflection of sunlight by clouds

(B) Scattering of light

(D) Diffraction of light

Answer

Answer: (C) Atmospheric refraction

45. Why does the sky appear blue?

(A) Due to the refraction of light

(B) Because of the absorption of red light

(D) Because blue light is the only visible wavelength

Answer

Answer: (C) Due to the scattering of shorter wavelengths of light

46. What is the phenomenon responsible for the blue color of the sky?

(A) Reflection

(B) Scattering

(D) Diffraction

Answer

Answer: (B) Scattering

47. Which scientist first explained the scattering of light?

(A) Isaac Newton

(B) Albert Einstein

(D) Galileo Galilei

Answer

Answer: (C) Lord Rayleigh

48. Why does the sky appear dark to astronauts in space?

(A) Because there is no scattering of light in space

(B) Because of the presence of cosmic dust

(D) Because light gets absorbed by space gases

Answer

Answer: (A) Because there is no scattering of light in space

49. Why is red light used in danger signals?

(A) Because it has the shortest wavelength

(B) Because it is least scattered by fog and dust

(D) Because it is the brightest color

Answer

Answer: (B) Because it is least scattered by fog and dust

50. Which effect is responsible for the visibility of light beams through a dusty room?

(A) Tyndall Effect

(B) Rayleigh Scattering

(D) Interference

Answer

Answer: (A) Tyndall Effect

Class 10 Science Chapter 10 The Human Eye and The Colourful World