Here’s a bank of 60 multiple-choice questions (MCQs) on the topic of geometrical optics, following your guidelines for difficulty levels and keeping the wording suitable for BISE, Gujranwala.
Easy Questions (30%)
1. What is the first law of reflection?
- A) The angle of incidence is equal to the angle of reflection.
- B) Light travels in a straight line.
- C) Light bends when it enters a different medium.
- D) The speed of light is constant.
2. Which of the following describes a spherical mirror?
- A) A mirror with a flat surface.
- B) A mirror that curves inward or outward.
- C) A mirror that only reflects light in one direction.
- D) A mirror that does not form images.
3. What is the formula for image location in a spherical mirror?
- A) 1/f = 1/v + 1/u
- B) v = u + f
- C) f = v - u
- D) u = v + f
4. Which type of lens is thicker at the center than at the edges?
- A) Concave lens
- B) Convex lens
- C) Bifocal lens
- D) Plano-convex lens
5. What happens to light rays when they enter a denser medium?
- A) They speed up.
- B) They bend away from the normal.
- C) They slow down and bend towards the normal.
- D) They do not change direction.
6. Which instrument uses a convex lens to magnify objects?
- A) Telescope
- B) Microscope
- C) Camera
- D) Projector
7. What is total internal reflection?
- A) Reflection of light off a smooth surface.
- B) Reflection of light when it hits a less dense medium.
- C) The complete reflection of light within a medium.
- D) The bending of light as it passes through a lens.
8. What does the power of a lens measure?
- A) The thickness of the lens.
- B) The ability of the lens to focus light.
- C) The distance between the lens and the object.
- D) The weight of the lens.
9. Which part of the human eye is responsible for focusing light?
- A) Retina
- B) Cornea
- C) Pupil
- D) Iris
10. What is the near point of the human eye?
- A) The farthest point from the eye that can be seen clearly.
- B) The closest point to the eye that can be seen clearly.
- C) The point where light enters the eye.
- D) The point of maximum light refraction.
Moderate Questions (40%)
11. What is the second law of reflection?
- A) Light can bend.
- B) Light travels in straight lines.
- C) The incident ray, reflected ray, and normal lie in the same plane.
- D) Light travels faster in a vacuum than in air.
12. What type of image is formed by a concave mirror when the object is placed beyond the center of curvature?
- A) Virtual and upright
- B) Real and inverted
- C) Real and upright
- D) Virtual and inverted
13. Which type of lens is used to correct hyperopia (farsightedness)?
- A) Concave lens
- B) Convex lens
- C) Bifocal lens
- D) Cylindrical lens
14. What is the focal length of a lens with a power of +2 diopters?
- A) 0.5 m
- B) 2 m
- C) 0.25 m
- D) 1 m
15. The image distance (v) in the lens formula (1/f = 1/v + 1/u) is taken as positive when?
- A) The image is virtual.
- B) The image is real.
- C) The object is on the left side of the lens.
- D) The lens is convex.
16. Which phenomenon explains the bending of light when it passes from one medium to another?
- A) Reflection
- B) Refraction
- C) Diffraction
- D) Dispersion
17. In a compound microscope, the objective lens has a shorter focal length than the eyepiece lens. What does this indicate?
- A) The objective lens is used for fine adjustment.
- B) The objective lens forms a real image.
- C) The eyepiece lens forms a virtual image.
- D) The objective lens is weaker than the eyepiece lens.
18. If the image distance is negative in the lens formula, what type of image is formed?
- A) Real
- B) Virtual
- C) Inverted
- D) Enlarged
19. What type of mirror is commonly used in cars for rearview mirrors?
- A) Convex mirror
- B) Concave mirror
- C) Plane mirror
- D) Spherical mirror
20. Which defect of vision is corrected by using a concave lens?
- A) Myopia (nearsightedness)
- B) Hyperopia (farsightedness)
- C) Astigmatism
- D) Presbyopia
21. What is the purpose of the iris in the human eye?
- A) To focus light
- B) To control the size of the pupil
- C) To protect the eye
- D) To detect light
22. In which type of lens is the focal point located on the opposite side of the incoming light?
- A) Convex lens
- B) Concave lens
- C) Bifocal lens
- D) Plano-concave lens
23. What happens to the speed of light as it passes from air into water?
- A) It increases
- B) It decreases
- C) It remains the same
- D) It becomes infinite
24. What type of image does a convex lens form when the object is located at the focal point?
- A) Real and inverted
- B) Virtual and upright
- C) No image is formed
- D) Real and enlarged
25. In telescopes, the objective lens is responsible for:
- A) Magnifying the image
- B) Focusing light from distant objects
- C) Providing a wide field of view
- D) Reducing glare
26. What is the primary defect of vision in which distant objects appear blurred?
- A) Myopia
- B) Hyperopia
- C) Astigmatism
- D) Presbyopia
27. What determines the brightness of an image formed by a lens?
- A) The focal length
- B) The size of the lens
- C) The distance from the light source
- D) The type of lens used
28. When light travels from a less dense to a denser medium, what happens to its speed and direction?
- A) Increases; bends away from normal
- B) Decreases; bends towards normal
- C) Remains constant; changes direction
- D) Increases; bends towards normal
29. What type of lens is used in a simple microscope?
- A) Concave lens
- B) Convex lens
- C) Cylindrical lens
- D) Bifocal lens
30. The focal length of a concave mirror is:
- A) Positive
- B) Negative
- C) Zero
- D) Infinite
Tough Questions (30%)
31. What is the image distance if a concave mirror forms an image that is three times the height of the object placed at a distance of 30 cm?
- A) 15 cm
- B) -10 cm
- C) 10 cm
- D) -15 cm
32. Which type of image formed by a lens is always inverted?
- A) Virtual
- B) Real
- C) Diminished
- D) Enlarged
33. What is the principal focus of a lens?
- A) The point where parallel rays converge.
- B) The center of the lens.
- C) The point from which rays diverge.
- D) The distance from the lens to the object.
34. The lens formula is given by 1/f = 1/v + 1/u. What does 'u' represent?
- A) Focal length
- B) Object distance
- C) Image distance
- D) Magnification
35. How does the power of a lens change if its focal length is halved?
- A) It doubles
- B) It halves
- C) It remains constant
- D) It quadruples
36. Which of the following statements about total internal reflection is true?
- A) It occurs when light travels from a denser to a rarer medium.
- B) It only happens at the critical angle.
- C) It can happen with any angle of incidence.
- D) It is the basis for fiber optics.
37. In the context of lenses, what does the term "virtual image" refer to?
- A) An image that cannot be projected on a screen.
- B) An image that is larger than the object.
- C) An image formed by rays that actually converge.
- D) An image that can be seen without a lens.
38. What is the role of the cornea in the human eye?
- A) To refract light and focus it onto the retina.
- B) To control the size of the pupil.
- C) To protect the eye from dust.
- D) To store images temporarily.
39. Which formula would you use to calculate the magnification of a lens?
- A) Magnification = Image distance/Object distance
- B) Magnification = Focal length/Object distance
- C) Magnification = Object distance/Image distance
- D) Magnification = Image distance + Object distance
40. When using a telescope, why are large objective lenses preferred?
- A) They provide a smaller field of view.
- B) They enhance color perception.
- C) They allow more light to enter and form clearer images.
- D) They reduce the weight of the telescope.
41. If a concave mirror has a radius of curvature of 40 cm, what is its focal length?
- A) 10 cm
- B) 20 cm
- C) 30 cm
- D) 40 cm
42. In a compound microscope, the eyepiece acts as a:
- A) Converging lens.
- B) Diverging lens.
- C) Reflecting lens.
- D) Refracting lens.
43. Which of the following is a characteristic of a real image formed by a lens?
- A) It is always upright.
- B) It can be projected on a screen.
- C) It is always smaller than the object.
- D) It cannot be captured on a photographic plate.
44. What occurs when light travels from air into glass at an angle greater than the critical angle?
- A) It is refracted.
- B) It is absorbed.
- C) It undergoes total internal reflection.
- D) It is transmitted through.
45. What is the approximate near point of a normal human eye?
- A) 25 cm
- B) 50 cm
- C) 100 cm
- D) 10 cm
46. Which of the following defects of vision can be corrected using a convex lens?
- A) Myopia
- B) Hyperopia
- C) Astigmatism
- D) Presbyopia
47. How is the brightness of an image in a microscope affected when using higher magnifications?
- A) Increases
- B) Decreases
- C) Remains the same
- D) Becomes variable
48. In a telescope, the distance between the objective lens and the eyepiece is known as the?
- A) Focal length
- B) Tube length
- C) Aperture
- D) Power
49. What type of mirror is used in a shaving mirror to produce a magnified image?
- A) Plane mirror
- B) Convex mirror
- C) Concave mirror
- D) Spherical mirror
50. Which of the following statements about lenses is true?
- A) Convex lenses diverge light rays.
- B) Concave lenses converge light rays.
- C) Lenses can be made of plastic or glass.
- D) Lenses do not have any focal length.
51. What is the far point of a person with hyperopia?
- A) Distant objects appear blurred.
- B) Close objects appear blurred.
- C) Both distant and close objects appear blurred.
- D) Objects at all distances are clear.
52. In which application is the principle of refraction utilized?
- A) Rearview mirrors
- B) Fiber optics
- C) Periscopes
- D) All of the above
53. What type of image is formed by a concave lens?
- A) Real and inverted
- B) Real and upright
- C) Virtual and upright
- D) Virtual and inverted
54. What happens to light rays when they pass through a convex lens?
- A) They diverge.
- B) They converge at a point.
- C) They reflect back.
- D) They become parallel.
55. The primary function of the pupil in the eye is to:
- A) Focus light onto the retina.
- B) Control the amount of light entering the eye.
- C) Form images of distant objects.
- D) Protect the eye from injury.
56. In a fiber optic cable, total internal reflection is used to:
- A) Increase the speed of light.
- B) Prevent loss of light.
- C) Focus light into a narrow beam.
- D) Bend light around corners.
57. Which type of lens is used in a projector?
- A) Concave lens
- B) Convex lens
- C) Plano-convex lens
- D) Cylindrical lens
58. What happens to the image formed by a convex lens when the object is placed at a distance less than the focal length?
- A) The image is real and inverted.
- B) The image is virtual and upright.
- C) No image is formed.
- D) The image is diminished and inverted.
59. What is the formula for calculating the magnifying power of a simple microscope?
- A) Focal length of the eyepiece / Focal length of the objective
- B) Focal length of the objective / Focal length of the eyepiece
- C) (Focal length of the eyepiece + Focal length of the objective)
- D) Focal length of the objective - Focal length of the eyepiece
60. What is the main purpose of a telescope?
- A) To magnify close objects.
- B) To allow distant objects to be viewed clearly.
- C) To reflect light.
- D) To measure the distance of stars.
Answers
1. A
2. B
3. A
4. B
5. C
6. B
7. C
8. B
9. B
10. B
11. C
12. B
13. B
14. A
15. A
16. B
17. B
18. B
19. A
20. A
21. B
22. A
23. B
24. C
25. C
26. A
27. C
28. B
29. B
30. B
31. D
32. B
33. A
34. B
35. A
36. D
37. A
38. A
39. A
40. C
41. B
42. A
43. B
44. C
45. A
46. B
47. B
48. B
49. C
50. C
51. A
52. D
53. C
54. B
55. B
56. B
57. B
58. B
59. A
60. B