You are given the following three leness. Which two lensee will you use as an eyepiece and as an objective to construct an astronomial telescope ? Give reason.

Your are given following three lense. Which two lenses will you use as an eyepiece and as an objective to construct as astronomical telescope ?

Which of the following concentration processes will you use when the gangue is light ?

You are given two identical bars, one of which is magnetised. How will you select the magnetised bar?

Give reasons for the following in one or two sentences : 'Graphite is used as a solid lubricant.''

Assuming the mean wavelength of light as 555 nm , estimate the smallest angular separation of two stars which can be just resolved by the telescope. Given the diameter of objective of astronomical telescope is 25 cm .

Suppose you are given a circle. Give a construction to find its centre.

Suppose you are given a circle. Give a construction to find its centre.

You are given three lenses of power 0.5 D , 4D and 10D to design a telescope. (i) Which lenses should be used as objective and eyepiece? Justify your answer. (ii) Why is the aperture of the objective preferred to be large ?

In which of the following figures, you find two polygons on the same base and between the same parallels?

Two convex lenses of same focal length but of aperture A_(1) and A_(2)(A_(2) lt A_(1)) are used as the objective lenses in two astronomical telescope having identical eye pieces. What is the ratio of their resolving power ? Which telescope will you prefer and why ? Give reason.