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 eyepiece of an astronomical telescope is 6 cm. What is the distance between the objective and the eyepiece if it produces a magnification of 10, for normal adjustment ?
The magnifying power of an astronomical telescope for relaxed vision is 16. On adjusting, the distance between the objective and eye lens is 34 cm . Then the focal length of objective and eye lens will be respectively
If f_o and f_e are the focal lengths of the objective lens and eye-piece lens respectively for a telescope, the length of telescope in normal adjustment is
The focal length of the objective and eyepiece of an astronomical telescope for normal adjustments are 50 cm and 5 cm. The length of the telescope should be:
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
A telescope has been adjusted for relaxed eye. How will you change the distance between objective lens and eye if final image is to be seen at the least distance of distinct vision ?
