Class 10 Science — The Human Eye and the Colourful World Question Bank
A. MCQs — Choose the Correct Answer
Human Eye & Accommodation
1. The image formed by the human eye on the retina is:
A. Virtual and erect
B. Real and inverted
C. Virtual and inverted
D. Real and erect
2. Most of the refraction of light entering the human eye occurs at the:
A. Retina
B. Iris
C. Outer surface of cornea
D. Eye lens
3. The amount of light entering the eye is controlled by the:
A. Retina
B. Pupil
C. Optic nerve
D. Ciliary muscles
4. The iris controls the:
A. Focal length of eye lens directly
B. Size of pupil
C. Position of retina
D. Shape of eyeball
5. The ability of the eye lens to adjust its focal length is called:
A. Dispersion
B. Accommodation
C. Refraction
D. Scattering
6. When viewing a nearby object, the ciliary muscles:
A. Relax and lens becomes thinner
B. Contract and lens becomes thicker
C. Relax and lens becomes thicker
D. Do not act
7. For a distant object, the eye lens generally becomes:
A. Thicker
B. More curved
C. Thinner
D. Opaque
8. The least distance of distinct vision for a young adult with normal vision is approximately:
A. 2.5 cm
B. 25 cm
C. 2.5 m
D. 25 m
9. The far point of a normal human eye is:
A. 25 cm
B. 25 m
C. 1 m
D. Infinity
10. The retina is best described as:
A. A muscular diaphragm
B. A light-sensitive membrane
C. A transparent covering
D. An opening in the eye
Defects of Vision
11. A person who can see nearby objects clearly but not distant objects suffers from:
A. Hypermetropia
B. Presbyopia
C. Myopia
D. Cataract
12. In myopia, the image of a distant object is formed:
A. Behind the retina
B. On the retina
C. In front of the retina
D. On the cornea
13. Myopia is corrected using a:
A. Convex lens
B. Concave lens
C. Plane mirror
D. Prism
14. Which of the following can cause myopia?
A. Eyeball becoming too short
B. Excessive curvature of eye lens
C. Loss of transparency of lens
D. Weakening of iris
15. A person who cannot see nearby objects distinctly but can see distant objects clearly suffers from:
A. Myopia
B. Hypermetropia
C. Cataract
D. Presbyopia only
16. In hypermetropia, light from a nearby object is focused:
A. In front of retina
B. Behind retina
C. On cornea
D. On iris
17. Hypermetropia is corrected using a:
A. Concave lens
B. Convex lens
C. Cylindrical lens only
D. Plane glass
18. Hypermetropia may arise because:
A. The eyeball has become too small
B. The eyeball has become too long
C. The eye lens has become excessively curved
D. The pupil has disappeared
19. Presbyopia is mainly associated with:
A. Childhood
B. Ageing
C. Excessive exposure to sunlight
D. Atmospheric refraction
20. Presbyopia occurs due to:
A. Increased flexibility of eye lens
B. Weakening of ciliary muscles and reduced flexibility of lens
C. Increased size of pupil
D. Increased transparency of lens
21. A person suffering from both myopia and hypermetropia may require:
A. A plane mirror
B. Bifocal lenses
C. Only a concave mirror
D. A prism only
22. In a common bifocal lens, the upper portion is:
A. Convex
B. Concave
C. Plane
D. Cylindrical
23. In a common bifocal lens, the lower portion is:
A. Concave
B. Convex
C. Plane
D. None of these
Prism & Dispersion
24. The angle between the two lateral faces of a prism is called:
A. Angle of incidence
B. Angle of deviation
C. Angle of prism
D. Angle of emergence
25. When light travels from air into glass, it bends:
A. Away from the normal
B. Towards the normal
C. Along the surface
D. Without deviation
26. When light travels from glass into air, it bends:
A. Towards the normal
B. Away from the normal
C. Along the normal only
D. It stops
27. The angle through which the emergent ray is deviated from the original direction is called:
A. Angle of prism
B. Angle of incidence
C. Angle of deviation
D. Critical angle
28. The splitting of white light into its component colours is called:
A. Reflection
B. Dispersion
C. Accommodation
D. Scattering
29. The sequence of colours produced by dispersion is:
A. ROYGBIV
B. VIBGYOR
C. VIBGYOR in reverse only
D. RGBYIVO
30. Which colour is deviated the least by a glass prism?
A. Violet
B. Blue
C. Green
D. Red
31. Which colour is deviated the most by a glass prism?
A. Red
B. Yellow
C. Violet
D. Orange
32. The coloured band obtained after dispersion is called the:
A. Spectrum
B. Beam
C. Image
D. Shadow
33. Newton’s experiment with a second inverted prism showed that the spectrum can be:
A. Absorbed
B. Recombined into white light
C. Converted into darkness
D. Reflected completely
Rainbow & Atmospheric Refraction
34. A rainbow is a natural:
A. Reflection
B. Spectrum
C. Shadow
D. Image
35. A rainbow is generally observed in a direction:
A. Towards the Sun
B. Opposite to the Sun
C. Directly above the Sun
D. At the position of the Sun
36. The tiny water droplets involved in rainbow formation act like:
A. Mirrors
B. Small prisms
C. Concave lenses
D. Plane slabs
37. Rainbow formation involves:
A. Only reflection
B. Only refraction
C. Dispersion, internal reflection and refraction
D. Only scattering
38. Twinkling of stars is caused by:
A. Dispersion
B. Atmospheric refraction
C. Reflection from clouds
D. Tyndall effect
39. Stars twinkle because they are:
A. Very close extended sources
B. Approximately point-sized sources
C. Non-luminous objects
D. Inside the atmosphere
40. Planets generally do not noticeably twinkle because they:
A. Produce no light
B. Are extended sources
C. Are farther away than stars
D. Have no atmosphere
41. The Sun is visible approximately two minutes before actual sunrise because of:
A. Scattering
B. Dispersion
C. Atmospheric refraction
D. Internal reflection
42. The apparent flattening of the Sun near sunrise and sunset is due to:
A. Atmospheric refraction
B. Dispersion
C. Tyndall effect
D. Reflection
Scattering of Light
43. The phenomenon in which the path of light becomes visible due to scattering by colloidal particles is called:
A. Accommodation
B. Tyndall effect
C. Dispersion
D. Refraction
44. The blue colour of the clear sky is mainly due to:
A. Reflection of blue light by oceans
B. Scattering of light
C. Dispersion by clouds
D. Refraction by water vapour alone
45. Fine particles in the atmosphere scatter which part of visible light more strongly?
A. Longer wavelengths
B. Shorter wavelengths
C. Only red light
D. All wavelengths equally
46. Red light is used for danger signals because it:
A. Has the shortest wavelength
B. Is scattered least by fog and smoke
C. Is scattered most strongly
D. Has no wavelength
47. If Earth had no atmosphere, the sky would appear:
A. Blue
B. Green
C. Dark
D. Red
48. At very high altitudes, the sky may appear dark because:
A. There is no sunlight
B. Atmospheric scattering is less prominent
C. Red light disappears
D. The Sun stops emitting blue light
B. Assertion–Reason Questions
Choose:
A. Both A and R are true, and R correctly explains A.
B. Both A and R are true, but R does not correctly explain A.
C. A is true, but R is false.
D. A is false, but R is true.
1.
Assertion: A normal eye can see objects clearly between about 25 cm and infinity.
Reason: The near point of a normal young adult eye is about 25 cm and its far point is infinity.
2.
Assertion: Myopia is corrected using a concave lens.
Reason: A concave lens helps bring the image of a distant object onto the retina.
3.
Assertion: Hypermetropia is corrected using a concave lens.
Reason: A convex lens provides additional converging power.
4.
Assertion: Presbyopia is associated with ageing.
Reason: The flexibility of the eye lens and the strength of ciliary muscles may decrease with age.
5.
Assertion: Red light is deviated least by a glass prism.
Reason: Different colours of light are deviated by different amounts.
6.
Assertion: A rainbow is formed opposite to the direction of the Sun.
Reason: Water droplets disperse sunlight and also internally reflect it.
7.
Assertion: Stars twinkle.
Reason: Starlight undergoes atmospheric refraction through changing atmospheric conditions.
8.
Assertion: Planets do not noticeably twinkle.
Reason: Planets are extended sources and variations from different parts tend to average out.
9.
Assertion: The sky appears blue.
Reason: Atmospheric particles scatter shorter wavelengths more strongly than longer wavelengths.
10.
Assertion: Red is used as a danger signal.
Reason: Red light is scattered least by fog and smoke.
C. Fill in the Blanks
1. The light-sensitive screen of the eye is called the ________.
2. The transparent bulge on the front surface of the eye is the ________.
3. The ________ controls the size of the pupil.
4. The pupil controls the amount of ________ entering the eye.
5. The ability of the eye lens to adjust its focal length is called ________.
6. The near point of a normal young adult eye is approximately ________ cm.
7. The far point of a normal eye is ________.
8. Myopia is also called ________.
9. Hypermetropia is also called ________.
10. Myopia is corrected by using a ________ lens.
11. Hypermetropia is corrected by using a ________ lens.
12. The age-related reduction in the power of accommodation is called ________.
13. The splitting of white light into its component colours is called ________.
14. The coloured band obtained from dispersion is called the ________.
15. The sequence of colours in the spectrum can be remembered using the acronym ________.
16. In a prism, ________ light bends the least.
17. In a prism, ________ light bends the most.
18. A rainbow is a natural ________.
19. Twinkling of stars is caused by atmospheric ________.
20. The phenomenon of scattering by colloidal particles is called the ________ effect.
21. The sky appears blue because shorter wavelengths are scattered more ________ than longer wavelengths.
22. Red light is scattered ________ by fog and smoke.
D. True or False
1. The retina is a light-sensitive membrane.
2. The iris directly forms the image on the retina.
3. The normal near point of a young adult is about 25 cm.
4. The far point of a normal eye is infinity.
5. Myopia is corrected with a convex lens.
6. Hypermetropia is corrected with a convex lens.
7. In myopia, a distant object’s image forms in front of the retina.
8. In hypermetropia, a nearby object’s image forms behind the retina.
9. Presbyopia is associated with ageing.
10. Violet light is deviated less than red light by a prism.
11. Dispersion separates white light into component colours.
12. A rainbow forms in the same direction as the Sun.
13. Twinkling of stars is an atmospheric refraction effect.
14. Planets noticeably twinkle because they are point sources.
15. The blue colour of the sky is due to scattering.
16. Red light is scattered more than blue light by atmospheric particles.
E. Match the Following
Set 1
| Column A | Column B |
|---|---|
| 1. Myopia | a. Convex lens |
| 2. Hypermetropia | b. Concave lens |
| 3. Presbyopia | c. Age-related loss of accommodation |
| 4. Retina | d. Light-sensitive membrane |
Set 2
| Column A | Column B |
|---|---|
| 1. Red | a. Greatest deviation |
| 2. Violet | b. Least deviation |
| 3. Dispersion | c. Splitting of white light |
| 4. Spectrum | d. Coloured band |
Set 3
| Column A | Column B |
|---|---|
| 1. Twinkling stars | a. Scattering |
| 2. Blue sky | b. Atmospheric refraction |
| 3. Rainbow | c. Dispersion + internal reflection + refraction |
| 4. Danger signal | d. Red light |
F. Very Short Answer Questions
1. What is accommodation of the eye?
2. What is the near point of a normal eye?
3. What is the far point of a normal eye?
4. What is the function of the iris?
5. What is the function of the pupil?
6. What is the function of the retina?
7. What is myopia?
8. What is hypermetropia?
9. What is presbyopia?
10. Which lens corrects myopia?
11. Which lens corrects hypermetropia?
12. What is a bifocal lens?
13. Define dispersion of white light.
14. What is a spectrum?
15. What is the angle of deviation?
16. Name the seven colours of the spectrum in order.
17. Which colour suffers minimum deviation through a prism?
18. Which colour suffers maximum deviation?
19. What is atmospheric refraction?
20. What causes the twinkling of stars?
21. Why do planets not noticeably twinkle?
22. What is the Tyndall effect?
23. Why is the sky blue?
24. Why are danger signals red?
G. Short Answer Questions
1. Explain the role of the ciliary muscles in accommodation.
2. Differentiate between the near point and far point of the eye.
3. Explain why a normal eye cannot see clearly an object placed much closer than 25 cm.
4. Explain myopia with its cause, image position and correction.
5. Explain hypermetropia with its cause, image position and correction.
6. What causes presbyopia? How can it be corrected?
7. Differentiate between myopia and hypermetropia.
8. Explain why bifocal lenses may be required by some people.
9. Describe what happens to a ray of light when it passes through a triangular prism.
10. What is meant by angle of deviation in a prism?
11. Why does white light split into different colours when passed through a prism?
12. Why does red light deviate less than violet light through a prism?
13. Explain Newton’s prism experiment and its conclusion.
14. Explain how a rainbow is formed.
15. Why is a rainbow seen opposite to the Sun?
16. Explain the twinkling of stars using atmospheric refraction.
17. Why don’t planets noticeably twinkle?
18. Explain advance sunrise and delayed sunset.
19. What is the Tyndall effect? Give two examples.
20. Explain why the clear sky appears blue.
21. Why does the sky appear dark to an astronaut at very high altitude?
22. Why are red lights preferred for danger signals?
H. Long Answer / 3–5 Mark Questions
1. Describe the structure and working of the human eye. Explain the functions of the cornea, iris, pupil, lens, retina and optic nerve.
2. Explain the power of accommodation of the human eye. Describe what happens to the eye lens when viewing near and distant objects.
3. Explain myopia in detail. Include:
- meaning
- causes
- image formation
- corrective lens
- working of correction
4. Explain hypermetropia in detail. Include:
- meaning
- causes
- image formation
- corrective lens
- working of correction
5. Explain presbyopia, its causes and correction. Also explain why bifocal lenses may be needed.
6. Explain refraction of light through a triangular glass prism and define the important angles involved.
7. Explain dispersion of white light through a prism. Why are different colours deviated by different amounts?
8. Explain the formation of a rainbow with a suitable labelled ray diagram.
9. Explain atmospheric refraction and discuss:
- twinkling of stars
- advance sunrise
- delayed sunset
10. Explain scattering of light and the Tyndall effect. Why does the sky appear blue and why are danger signals red?
I. Diagram-Based Questions
1. Human Eye
Draw a neat, labelled diagram of the human eye and identify:
- Cornea
- Iris
- Pupil
- Eye lens
- Ciliary muscles
- Retina
- Optic nerve
2. Accommodation
Draw two simple diagrams showing the eye focusing on:
(a) a distant object
(b) a nearby object
Show the change in the eye lens.
3. Myopia
Draw a ray diagram showing:
- formation of the image before the retina
- correction using a concave lens
4. Hypermetropia
Draw a ray diagram showing:
- formation of the image behind the retina
- correction using a convex lens
5. Prism
Draw a labelled ray diagram showing:
- incident ray
- refracted ray
- emergent ray
- angle of incidence
- angle of refraction
- angle of emergence
- angle of prism
- angle of deviation
6. Dispersion
Draw a prism diagram showing white light entering the prism and the VIBGYOR spectrum emerging.
7. Rainbow
Draw a labelled diagram showing the path of sunlight through a raindrop involving:
refraction → dispersion → internal reflection → refraction
J. Case-Based Questions
Case 1 — A Student at the Back of the Classroom
A student can read a book comfortably but cannot clearly read what is written on the classroom blackboard from the last row.
Questions:
- Which defect of vision is likely present?
- Where does the image of a distant object form in this defect?
- Which type of lens is required?
- Give one possible cause of this defect.
Case 2 — Difficulty Reading Nearby
A person can see distant objects clearly but has difficulty reading a book at the normal reading distance.
Questions:
- Which defect could be present?
- Where is the image of a nearby object formed?
- Which lens can correct it?
- What happens to the near point in this condition?
Case 3 — Prism Experiment
A narrow beam of sunlight is allowed to pass through a triangular glass prism and a coloured band appears on a screen.
Questions:
- Name the phenomenon.
- What is the coloured band called?
- Write the colours in order.
- Which colour deviates least?
- Which colour deviates most?
Case 4 — A Rainbow After Rain
A student observes a rainbow after rainfall while the Sun is behind them.
Questions:
- What acts like tiny prisms?
- What happens to sunlight inside the droplets?
- What other optical phenomenon occurs besides dispersion?
- In which direction relative to the Sun is the rainbow seen?
Case 5 — Night Sky
A student notices that stars appear to flicker, whereas planets generally appear steady.
Questions:
- What causes the flickering of stars?
- Why are stars treated approximately as point sources?
- Why don’t planets noticeably twinkle?
- Name the atmospheric phenomenon responsible.
Case 6 — Blue Sky and Red Signals
A student notices that the daytime sky is blue and that red lights are used as danger signals.
Questions:
- What phenomenon causes the blue sky?
- Which wavelengths are scattered more strongly by fine atmospheric particles?
- Why does red light travel more effectively through fog or smoke?
- Why would the sky look dark if Earth had no atmosphere?
K. Numerical Questions
Lens Power
1. A corrective lens has a power of –5.5 D. Calculate its focal length.
2. A lens has a power of +1.5 D. Calculate its focal length.
3. A lens has focal length –0.20 m. Find its power and identify its type.
4. A lens has focal length +0.50 m. Find its power and identify its type.
Myopia
5. The far point of a myopic person is 80 cm in front of the eye. Determine the nature and approximate power of the corrective lens required.
6. A myopic person cannot see objects clearly beyond 1.2 m. What type of lens is required to correct the defect?
Hypermetropia
7. A hypermetropic person’s near point is 1 m. The near point of a normal eye is 25 cm. Determine the power of the corrective lens.
8. A person needs a convex lens of suitable power to correct near vision. Explain why the lens must be converging.
L. HOTS / Conceptual Questions
1. If the eye lens could not change its focal length, what would happen to accommodation?
2. Why is the crystalline lens not responsible for all of the refraction occurring in the eye?
3. Why does the image formed on the retina need to be interpreted by the brain?
4. A person can see a book clearly but not the blackboard. What does this tell you about the person’s far point?
5. If the eyeball becomes elongated, which vision defect can result? Explain.
6. If the eyeball becomes too small, which vision defect can result? Explain.
7. Why does placing a convex lens before a hypermetropic eye help it see nearby objects?
8. Why does a concave lens help a myopic eye see distant objects?
9. Why does a prism separate colours whereas a rectangular glass slab does not produce a visible spectrum in the same way?
10. Why does the second inverted prism in Newton’s experiment produce white light?
11. Why is a rainbow not normally seen when the Sun is directly overhead?
12. Why can a rainbow sometimes be observed near a fountain or waterfall?
13. Why does the apparent position of a star differ from its actual position?
14. Why does atmospheric refraction cause the apparent position of a star to fluctuate?
15. Why is the effect of atmospheric refraction on a planet less noticeable than on a star?
16. Why does the Sun appear flattened near the horizon?
17. Why does the colour of scattered light depend on particle size?
18. Why would the sky not appear blue in the absence of an atmosphere?
19. Why is blue scattered more strongly than red by very fine atmospheric particles?
20. Why is red light more suitable than blue light for danger signals?
M. Assertion/Concept Challenge
Complete each statement with the best scientific reason.
1. A normal eye can focus both near and distant objects because ________.
2. A myopic eye needs a concave lens because ________.
3. A hypermetropic eye needs a convex lens because ________.
4. An old person’s near point may move farther away because ________.
5. A prism produces a spectrum because ________.
6. Violet deviates more than red because ________.
7. A rainbow contains different colours because ________.
8. Stars twinkle because ________.
9. Planets do not noticeably twinkle because ________.
10. The sky appears blue because ________.
11. Red danger signals remain visible through fog because ________.
ANSWER KEY
MCQs
| Q | Ans | Q | Ans | Q | Ans |
|---|---|---|---|---|---|
| 1 | B | 17 | B | 33 | B |
| 2 | C | 18 | A | 34 | B |
| 3 | B | 19 | B | 35 | B |
| 4 | B | 20 | B | 36 | B |
| 5 | B | 21 | B | 37 | C |
| 6 | B | 22 | B | 38 | B |
| 7 | C | 23 | B | 39 | B |
| 8 | B | 24 | C | 40 | B |
| 9 | D | 25 | B | 41 | C |
| 10 | B | 26 | B | 42 | A |
| 11 | C | 27 | C | 43 | B |
| 12 | C | 28 | B | 44 | B |
| 13 | B | 29 | B | 45 | B |
| 14 | B | 30 | D | 46 | B |
| 15 | B | 31 | C | 47 | C |
| 16 | B | 32 | A | 48 | B |
Fill in the Blanks
- Retina
- Cornea
- Iris
- Light
- Accommodation
- 25
- Infinity
- Near-sightedness
- Far-sightedness
- Concave
- Convex
- Presbyopia
- Dispersion
- Spectrum
- VIBGYOR
- Red
- Violet
- Spectrum
- Refraction
- Tyndall
- Strongly
- Least
True / False
- True
- False
- True
- True
- False
- True
- True
- True
- True
- False
- True
- False
- True
- False
- True
- False
Match the Following
Set 1
1-b, 2-a, 3-c, 4-d
Set 2
1-b, 2-a, 3-c, 4-d
Set 3
1-b, 2-a, 3-c, 4-d
High-Priority Questions for Exam Revision
If time is limited, do these first:
- Explain accommodation of the eye.
- Myopia — causes, ray diagram and correction.
- Hypermetropia — causes, ray diagram and correction.
- Presbyopia and bifocal lenses.
- Refraction through a prism + angle of deviation.
- Dispersion + VIBGYOR.
- Rainbow formation with diagram.
- Why do stars twinkle?
- Why don’t planets twinkle?
- Explain advance sunrise and delayed sunset.
- Explain Tyndall effect.
- Why is the sky blue?
- Why are danger signals red?
- Solve lens-power numericals.
- Draw and label the correction diagrams for myopia and hypermetropia.