The length of a telescope is 36 cm . The focal lengths of its lenses can be

The length of an astronomical telescope is 40 cm. The focal lengths of its lenses will be

A telescope has a magnification equal to 5 and the length of its tube is 60 cm. The focal length of its eye piece is

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 eye piece is found to be 80 cm . The magnifying power of the telescope is 19 . The focal length of the lenses are

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 focal length of the objective of a terrestrial telescope is 80 cm and it is adjusted for parallel rays, then its magnifying power is 20. If the focal length of erecting lens is 20 cm , then full length of telescope will be