English

Draw a Labeled Ray Diagram of a Reflecting Telescope. Mention Its Two Advantages Over the Refracting Telescope.

Advertisements
Advertisements

Question

Draw a labeled ray diagram of a reflecting telescope. Mention its two advantages over the refracting telescope.

Advertisements

Solution

Reflecting Telescope,

Its two advantages over Refracting telescope:

1. It reduces the spherical aberration and forms a clear focused image.

2. It doesn’t require a lens of very large aperture as refracting type requires that cannot be manufactured easily.

shaalaa.com
  Is there an error in this question or solution?
2011-2012 (March) All India Set 1

RELATED QUESTIONS

Draw a labeled ray diagram to obtain the real image formed by an astronomical telescope in normal adjustment position. Define its magnifying power.


A small telescope has an objective lens of focal length 144 cm and an eyepiece of focal length 6.0 cm. What is the magnifying power of the telescope? What is the separation between the objective and the eyepiece?


  1. A giant refracting telescope at an observatory has an objective lens of focal length 15 m. If an eyepiece of focal length 1.0 cm is used, what is the angular magnification of the telescope?
  2. If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens? The diameter of the moon is 3.48 × 106 m, and the radius of lunar orbit is 3.8 × 108 m.

You are given three lenses of power 0.5 D, 4 D, and 10 D to design a telescope.

1) Which lenses should be used as objective and eyepiece? Justify your answer.

2) Why is the aperture of the objective preferred to be large?


With regard to an astronomical telescope of refracting type~ state how you will increase its:

1) magnifying power

2) resolving power


A Galilean telescope is 27 cm long when focussed to form an image at infinity. If the objective has a focal length of 30 cm, what is the focal length of the eyepiece?


A lady cannot see objects closer than 40 cm from the left eye and closer than 100 cm from the right eye. While on a mountaineering trip, she is lost from her team. She tries to make an astronomical telescope from her reading glasses to look for her teammates. (a) Which glass should she use as the eyepiece? (b) What magnification can she get with relaxed eye?


(i) What is meant by resolving power of a telescope?
(ii) State any one method of increasing the resolving power of an astronomical telescope.


Draw a ray diagram for the formation of image of an object by an astronomical telescope, in normal adjustment. Obtain the expression for its magnifying power.


The magnifying power of an astronomical telescope in normal adjustment is 2.9 and the objective and the eyepiece are separated by a distance of 150 cm. Find the focal lengths of the two lenses.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×