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A convex lens made of glass forms a sharp image on the screen for a particular position of an object with respect to the lens. A human eye lens is also a convex lens but it can form sharp images on the retina of eye for different positions of the objects. Explain, why?
What is short-sightedness? How can this defect be corrected?
How is a normal eye able to see distinctly distant as well as nearer objects? What is the distance of distinct vision?
Why do we have two eyes instead of one eye?
For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
Assertion: A beam of white light gives a spectrum on passing through a hollow prism.
Reason: Speed of light outside the prism is different as the speed of light inside the prism.
What is presbyopia? State the cause of Presbyopia. How is presbyopia of a person be corrected?
For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both A and R are true, and R is correct explanation of the assertion.
(b) Both A and R are true, but R is not the correct explanation of the assertion.
(c) A is true, but R is false.
(d) A is false, but R is true.
Assertion: There is no dispersion of light refracted through a rectangular glass slab.
Reason: Dispersion of light is the phenomenon of splitting of a beam of white light into its constituents’ colours.
When we enter a dim-lit room from a bright light, we are not able to see the object in the room for some time.
Explain, why?
Or
Why does it take some time to see objects in a cinema hall when we just enter the hall from bright sun light? Explain.
What is long-sightedness? How can this defect be corrected?