Question

Read the passage given below and answer the question that follows.

There are two types of optical instruments: Microscopes and Telescopes. Microscopes are used to magnify very tiny objects whereas telescopes are used to study distant objects. Both of them deploy convex lenses. In his telescope, Newton used a large parabolic mirror to collect light from the stars and reduce aberrations.

1. Rohit observed the launch of Chandrayan 3 with the help of an optical instrument. Name the instrument used by him.
2. State any one advantage of a reflecting telescope over a refracting telescope.
3. Which instrument is used to study the structure of a virus?
4. What is the ability of an optical instrument to form enlarged images called?
5. What is the difference between a compound microscope and an astronomical telescope (refracting type), as far as their lenses are concerned?

Useful Constants & Relations:

1	Charge of a proton	e	1.6 × 10-19 C
2	Speed of light in vacuum	c	3 × 108 ms-1
		1 u = 931 MeV

Answer 1

1. Telescope
2. When two telescopes of the same size are used for reflection and refraction, the reflecting telescope produces a brighter image. Moreover, a reflecting telescope's image is free of chromatic aberration, or colour orbit distortion.
3. Microscope
4. Magnifying power
5. When using an astronomical telescope, the objective lens's focal length is greater than the eyepiece; however, in a compound microscope, it is less than the eyepiece.