Question

Which of the below-given option is correct about an astronomical telescope?

• A. The image produced by the telescope is inverted
• B. Its objective is a concave lens
• C. Telescopes consists of two diverging lenses
• D. Its eyepiece is a convex lens with a greater focal length than the objective lens.

Answer 1

The correct option is A

The image produced by the telescope is inverted

The explanation of the correct option

In the case of option A,

1. An astronomical telescope is a device that is used to magnify and view distant objects such as planets and stars.
2. It is made up of two convex lenses that are co-axially positioned so that the focal length of the objective is greater than the focal length of the eyepiece.
3. The focal length of an astronomical telescope is small due to this the final image produced by it is inverted, magnified, and virtual

The explanation for the incorrect options

In the case of option B,

1. An astronomical telescope consists of two convex lenses known as the objective and eyepiece.
2. The objective has a long focal length, but the eyepiece has a short focal length.

In the case of option C,

1. A convex lens is called a converging lens whereas a concave lens is called a diverging lens.
2. An astronomical telescope consists of two convex lenses known as the objective and eyepiece

In the case of option D,

1. The eyepiece of an astronomical telescope is a convex lens whose focal length is smaller than the focal length of the objective.
2. The focal length of a telescope is defined as the distance between the primary lens and the point at which light rays come together in focus.

Hence, option A is the correct answer.