What is the function of the circular stop at the focal plane of the objective of a telescope? Givereasons.

The aperture and focal length of the objective of telescope are large, why?

Consider the following statements about a microscope and a telescope 1. Both the eyepiece and the objective of a microscope are convex lenses. 2. The focal length of the objective of a telescope is lerger than the focal length of its eyepiece. 3. The magnification of a telescope increases with the increases in focal length of its objective. 4. The magnification of a microscope increases with the increases in focal length of its objective. Which of the statements given above are correct?

The magnifying power of terrestrial telescope is 25 when it is in normal adjustment and the length of the telescope is 124 cm. If the focal length of the erecting lens is 5 cm, the focal lengths of the objective and the eye-piece are respectively.

why should objective of a telescope have larger focal length ?

On seeing with unaided eye, the visual angle of moon at the eye is 0.6^(@) . The focal lengths of the objective and the eyepiece of a telescope are respectively 200 cm and 5 cm. What will the visual angle on seeing through the telescope?

Assertion : If objective and eye lenses of a microscope are interchanged then it can work as telescope. Reason : The objective of telescope has small focal length.

An astronomical telescope arranged for normal adjustment has a magnification of 6. If the length of the telescope is 35cm, then the focal lengths of objective and euye piece respectivley =, are