When a telescope is adjusted for parallel light, the distance of the objective from the eye piece is found to be `80 cm`. The magnifying power of the telescope is 19 . The focal length of the lenses are

When a telescope is adjusted for parallel light, the distance of the objective from the eyepiece is 100 cm for normal adjustment. The magnifying power of the telescope in this case is 9. If an old man cannot see beyond 90 cm and wishes to use the telescope, then he will have to reduce the tube length by

When a telescope is in normal adjusment, the distance of the objective from the eyepiece is found to 100 cm . If the magnifying power of the telescope, at normal adjusment, is 24 focal lengths of the lenses are

In an astronomical telescope, the distance between the objective lens and eyepiece is 20 cm. In normal adjustment, the magnifying power of the telescope is 15. Find the focal length of the objectives lens.

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

In an astronomical telescope, the focal length of the objective lens is 100 cm and of eye-piece is 2 cm . The magnifying power of the telescope for the normal eye is

The magnifying power of a telescope is 9. When it is adjusted for parallel rays the distance between the objective and eyepiece is 20cm . The focal lengths of lenses are

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