Home
Class 12
PHYSICS
An astronomical telescope has an angular...

An astronomical telescope has an angular magnification of magnitude 5 for distant objects. The separation between the objective and eye-piece is 36 cm and the final image is formed at infinity. The focal lengths of objective and eye piece.

A

30 cm

B

15 cm

C

20 cm

D

40 cm.

Text Solution

Verified by Experts

Promotional Banner

Similar Questions

Explore conceptually related problems

The total magnification produced by a compound microscope is 20. The magnification produced by the eye piece is 5. The microscope is focussed on a certain object. The distance between the objective and eyepiece is observed to be 14cm. If the least distance of distinct vision is 20cm, calculate the focal length of the objective and the eye piece.

(a) Draw a labelled ray diagram of an astronomical telescope to show the image formation of a distant object. Write the main consideration required in selecting the objective and eyepiece lenses in order to have large magnifying power an dhigh resolution of the telescope. (b) A compound microscope has an objective of focal length 1.25cm and eyepiece of focal lenth 5 cm. A small object is kept at 2.5 cm from the objective. If the final image formed is at infinity, find the distance between the objective and the eyepiece.

The focal length of the objective of a telescope is 60 cm. To obtain a magnification of 20, the focal length of the eye-piece should be :

An astronomical telescope is set for normal adjustment and the distance between its objective and eye piece is 1.05 cm. The magnifying power of the telescope is 20. What is the focal length of the objective ?

(a) Draw a neat labelled ray diagram showing the image formation of a distant object by a refracting telescope. Deduce the expression for its magnifying power when the final image is formed at infinity. (b) The sum of focal lengths of the two lenses of a refracting telescope is 105 cm. The focal length of one lens is 20 times that of the other. Determine the total magnification of the telescope when the final image is formed at infinity.

The distance between the object and real image formed by a lens is D . If the magnification is m , then the focal length of the lens is given by :

The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and the eyepiece is found to be 20 cm. The focal length of lenses are :

In compound microscope, length of microscope is 21.5 cm, focal length of objective is 1.6 cm, focal length of eye piece is 2.1 cm and if final image is formed at infinity then distance of the object from objective lens is