Home
Class 12
PHYSICS
The focal length of an objective of a te...

The focal length of an objective of a telescope is 3 metre and diameter 15 cm . Assuming for a normal eye, the diameter of the pupil is 3 mm for its complete use, the focal length of eye piece must be

A

6 cm

B

6.3 cm

C

20 cm

D

60 cm

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS

    CENGAGE PHYSICS|Exercise DPP 1.5|15 Videos

  • PHOTOELECTRIC EFFECT

    CENGAGE PHYSICS|Exercise Integer Type|4 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    CENGAGE PHYSICS|Exercise QUESTION BANK|40 Videos

Similar Questions

Explore conceptually related problems

The focal length of the eye-piece of compound microscope is

The focal length of the objective lens of a telescope is 50 cm If the magnification of the telescope is 25, then the focal length of the eye-piece is

If the focal length of the ey piece of the telescope is doubled, then its magnifying power (m) will be

The focal length of the objective lens of a telescope is 30 cm and that of its eye lens is 3 cm. It is focussed on a scale 2 metres distant from it. The distance of the objective lens from the eye lens to see with relaxed eye is :-

The focal length of the objective of an astronomical telescope is 1.0 m. If the magnifying power of the telescope is 20, find the focal length of the eyepiece and the length of the telescope for the relaxed eye.

The objective of an astronomical telescope has a focal length of 80cm . The telescope is focused for normal vision of distant objects when the tube length is 1.0m .If the focal length of eye piece is f_(e) (in cm ) and magnifying power of telescope is m then the value of (f_(e))/(m) is :

The focal lengths of the objective and eye lenses of a telescope are respectively 200 cm and 5 cm . The maximum magnifying power of the telescope will be

A telescope has magnification 5 and length of tube 60cm then the focal length of eye piece is–

The focal length of the objective of an astronomical telescope is 75 cm and that of the eye-piece is 5 cm. If the final image is formed at the least distance of distinct vision from the eye, calculate the magnify- ing power of the telescope.