Chapetr-10. Light-Reflection and Refraction
Q – By which muscles of eye can change the curvature of eye lens?
A – ciliary muscle.
Q - Whose reflective index is greater hot wind or cool wind? Why?
A – cool wind has greater reflective index. As cool wind is heavier than hot wind.
Q – A optician makes a lens using two different lenses converging and diverging lenses. Which kind of this lens is?
A – bifocal lens.
Q – Why does pencil look turned sinking in glass?
A – The pencil looks turned sinking in the glass due to refraction of light.
Q- Why does the sky appear dark instead of blue to an astronaut?
Q- What is cataract? How can it be removed?
A- The Crystalline lens of people at old age becomes milky and cloudy. This Condition is called cataract. This causes partial or complete loss od vision. This situation of eye is called cataract. It is possible to restore vision through a cataract surgery.
Q – Which colour deviates the minimum and the maximum, while white light passing through prism? Why?
A – Give two reasons for occurring myopia. Draw a ray diagram, how is this defect of vision corrected?
Q: What do you understand by atmospheric refraction? Name two phenomenon caused by this.
Give answers of the following questions;
(i) How does rainbow form?
(ii) What is called the light which forms spectrum similar to sun light?
(iii) What is called the splitting of light into its component colours?
(iv) Who works as a prism to form rainbow?
(v) Why does the sun appear before the actual sunrise and after actual sunset?