Question List-Human Eye and Colourful World

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This is a question list for 5th lesson- Human Eye and Colorful World, Physical Science text-book. Happy Solving.




  1. What is least distance of distinct vision?
  2. What is the angle of vision?
  3. How do you appreciate the role of ciliary muscles?
  4. What is the role of iris?
  5. How does iris help the pupil as a variable aperture?
  6. What are ‘rods’ and ‘cones’?
  7. Calculate the minimal focal length of eye.
  8. Calculate the maximum focal length of eye.
  9. What is accommodation of lens?
  10. What do you understand by far-point?
  11. What do you understand by near-point?
  12. How do you correct the following defects-
    1. Myopia
    2. Hypermetropia
    3. Presbyopia
  13. Define Power of Lens. Write its unit.
  14. Find the focal length of a lens of power, -2 D. What type of lens is this?
  15. A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
  16. A student has difficulty in reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?
  17. What is a prism?
  18. Show refraction of a light ray through a prism.
  19. Through a model graph show the variation between angle of incidence and angle of deviation.
  20. Light of wavelength  L1 enters a medium with refractive index n2 from a medium with refractive index n1. What is the wavelength of light in second medium?
  21. Write an expression for finding the refractive index of glass prism.
  22. What is dispersion of light?
  23. Through a diagram, show refraction and dispersion of light in a water drop.
  24. What is scattering of light?
  25. A light of wavelength 500nm travels in air. Find its frequency.
  26. What is scattering centre?
  27. Why is sky blue in colour?
  28. Why does sky appear white during noon time?
  29. Why does sky appear red or orange in colour during sunrise and sunset?
  30. What is Raman Effect? How is it used in identifying molecules?
  31. Why does rainbow appear like a “bow”?
  32. When do we observe a rainbow?
  33. Draw a structure of human eye and label parts.
  34. Anitha can only see objects beyond 50 cm from her eyes. Which lens is preferable to correct her vision. What should be its power?
  35. Which colour has the shortest wavelength?
  36. Which colour has the smallest frequency?
  37. Write a relation between frequency and wavelength of light.
  38. What happens to your eye when you enter a darkened cinema hall from bright sunshine? (or) Why does it take some time to see objects in dim room when you enter the room from bright sunshine outside?
  39. Explain the functions of the following parts of the eye
    1. Cornea
    2. Pupil
    3. Retina
    4. Optic nerve
  40. Consider the following 2 situations. The eyes of a person are focused on
    1.  on a nearby object
    2. on a distant object.

In which case, the focal length of eye-lens will be maximum? In which case, the converging power of eye-lens will be maximum?



  1. Discuss the structure of eye briefly.
  2. Explain how accommodation of eye lens is vital for us to visualize the world.
  3. What is short-sight?  Discuss this accommodation defect in detail. How to rectify this defect? Draw Diagrams.
  4. What is long-sight?  Discuss this accommodation defect in detail. How to rectify this defect? Draw Diagrams.
  5. What is Presbyopia? How to rectify this eye defect.
  6. How would you find the refractive index of a prism experimentally.
  7. Derive an expression for finding the refractive index of a prism.
  8. Discuss the formation of rainbow.
  9. Discuss briefly on scattering of light?
  10. Through an experiment, explain how particle size affects scattering of light.


Questions-Human Eye