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

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.

You are provided with two convex lenses having focal lengths 4cm and 80cm, respectively, to form an astronomical telescope. Calculate its magnifying power for normal adjustment.

Lenses used by those who cannot see near objects are

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 .

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 ?

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.

You are given two identical plano-convex lenses. When you palce an object 20cm to the left of a single plano-convex lens, the image appears 40cm to the right of the lens. You then arrange the two plano-convex lenses back to back to form a double convex lens. If the object is 20cm to th eleft of this new lens, what is the approximate location of the image?

In a compound microscope, the focal lengths of two lenses are 1.5 cm and 6.25 cm an object is placed at 2 cm form objective and the final image is formed at 25 cm from eye lens. The distance between the two lenses is

Four lenses A, B, C and D of power +100D, -50D, 20D and 5D. Which lenses will you use to design a compound microscope for best magnification ?

In which of the following the final image is erect? A) simple microscope B) compound microscope C) Astronomical telescope D) Galilean telescope