- Draw a neat and labeled diagram of the human eye.
- State the function of the crystalline lens in the human eye.
- What is the role of the iris and pupil in controlling the amount of light entering the eye?
- Define 'Power of Accommodation' of the eye. What is the maximum accommodation power for a normal
eye?
- Why is the blind spot called so? Explain its location.
- What is the function of the retina? Name the two types of photoreceptor cells present in it.
- Explain why we cannot see clearly for some time when we enter a dark room from bright sunlight.
- What is the range of vision for a normal human eye? Define Near point and Far point.
- Why does the eye lens not form a blurred image on the retina when viewing objects at different
distances?
- State the role of ciliary muscles in the working of the eye.
- What is the function of the optic nerve?
- Why do we have two eyes for vision instead of one? (Give two reasons).
- What happens to the pupil when you shine a torch into someone's eyes?
- Is the image formed on the retina real or virtual? Explain.
- What keeps the eye lens in its position?
- What is Myopia? Draw a ray diagram to show the image formation in a myopic eye.
- How is Myopia corrected? Draw a diagram to show the correction.
- List two main causes of Myopia.
- What is Hypermetropia? Draw a ray diagram to show the image formation in a hypermetropic eye.
- How is Hypermetropia corrected? Draw a ray diagram to show the correction.
- List two main causes of Hypermetropia.
- Differentiate between the Near Point of a Myopic eye and a Hypermetropic eye.
- What is Presbyopia? Why does it occur?
- How is Presbyopia corrected? What is a bifocal lens?
- A student cannot read the blackboard while sitting in the last row. Name the defect he is suffering
from. What kind of lens will the doctor suggest?
- A person needs a lens of power -5.5 D for distant vision. What is the focal length of the lens
required? Name the defect.
- A person needs a lens of power +1.5 D for correcting his near vision. What is the focal length of
the lens? Name the defect.
- Explain why a hypermetropic person prefers to remove his spectacles while looking at distant
objects.
- Can a person suffer from both Myopia and Hypermetropia? If yes, name the defect and its correction.
- What is Cataract? How can it be corrected?
- Draw a ray diagram for the refraction of light through a glass prism. Label the angle of incidence
($i$), angle of refraction ($r$), angle of emergence ($e$), and angle of deviation ($D$).
- Define Angle of Deviation. On what factors does it depend?
- What is meant by the dispersion of white light? Name the colors in the sequence they appear.
- Which color of white light bends the least and which bends the most during dispersion? Give reason.
- Explain the cause of dispersion of light through a glass prism.
- Draw a diagram to show the formation of a spectrum of white light.
- Who discovered that white light consists of seven colors? Describe his experiment with two prisms
(Newton's Recombination).
- Is the speed of light for all colors the same in a glass prism? Explain.
- How is a Rainbow formed? Name the three phenomena involved in its formation.
- What are the necessary conditions for observing a rainbow?
- Why does a rainbow appear as a bow (arc)?
- What is a monochromatic light? Can a prism disperse monochromatic light?
- Why does the red light bend the least in a prism?
- Differentiate between dispersion produced by a glass slab and a glass prism.
- What is a primary rainbow and a secondary rainbow? (Briefly).
- What is atmospheric refraction? Why does it occur?
- Explain why stars twinkle while planets do not.
- Why do stars appear slightly higher than their actual position? Explain with a diagram.
- Explain the phenomenon of 'Advanced Sunrise and Delayed Sunset'. By how much time is the day
lengthened?
- Why does the apparent position of a star fluctuate?
- What is Scattering of light? State the factors on which it depends.
- What is Tyndall Effect? Give two examples observed in daily life.
- Why does the clear sky appear blue? Explain.
- What would be the color of the sky for an astronaut in space? Why?
- Why do danger signal lights use red color?
- Why does the Sun appear reddish at sunrise and sunset? Explain with a diagram.
- Why does the Sun appear white at noon?
- Explain the blue color of water in deep sea.
- What is the relation between the wavelength of light and intensity of scattering (Rayleigh's Law)?
- Why does smoke appear blue?
