This is a question list for 5th lesson- Human Eye and Colorful World, Physical Science text-book. Happy Solving.
TOPIC: HUMAN EYE AND COLOURFUL WORLD
SHORT Q & A (2 OR 1 MARKS)
- What is least distance of distinct vision?
- What is the angle of vision?
- How do you appreciate the role of ciliary muscles?
- What is the role of iris?
- How does iris help the pupil as a variable aperture?
- What are ‘rods’ and ‘cones’?
- Calculate the minimal focal length of eye.
- Calculate the maximum focal length of eye.
- What is accommodation of lens?
- What do you understand by far-point?
- What do you understand by near-point?
- How do you correct the following defects-
- Define Power of Lens. Write its unit.
- Find the focal length of a lens of power, -2 D. What type of lens is this?
- 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?
- 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?
- What is a prism?
- Show refraction of a light ray through a prism.
- Through a model graph show the variation between angle of incidence and angle of deviation.
- 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?
- Write an expression for finding the refractive index of glass prism.
- What is dispersion of light?
- Through a diagram, show refraction and dispersion of light in a water drop.
- What is scattering of light?
- A light of wavelength 500nm travels in air. Find its frequency.
- What is scattering centre?
- Why is sky blue in colour?
- Why does sky appear white during noon time?
- Why does sky appear red or orange in colour during sunrise and sunset?
- What is Raman Effect? How is it used in identifying molecules?
- Why does rainbow appear like a “bow”?
- When do we observe a rainbow?
- Draw a structure of human eye and label parts.
- Anitha can only see objects beyond 50 cm from her eyes. Which lens is preferable to correct her vision. What should be its power?
- Which colour has the shortest wavelength?
- Which colour has the smallest frequency?
- Write a relation between frequency and wavelength of light.
- 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?
- Explain the functions of the following parts of the eye
- Optic nerve
- Consider the following 2 situations. The eyes of a person are focused on
- on a nearby object
- 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?
4 MARKS Q & A
- Discuss the structure of eye briefly.
- Explain how accommodation of eye lens is vital for us to visualize the world.
- What is short-sight? Discuss this accommodation defect in detail. How to rectify this defect? Draw Diagrams.
- What is long-sight? Discuss this accommodation defect in detail. How to rectify this defect? Draw Diagrams.
- What is Presbyopia? How to rectify this eye defect.
- How would you find the refractive index of a prism experimentally.
- Derive an expression for finding the refractive index of a prism.
- Discuss the formation of rainbow.
- Discuss briefly on scattering of light?
- Through an experiment, explain how particle size affects scattering of light.