Question

(a)State two main considerations taken into account while choosing the objective of

astronomical telescope.

(b) Draw a ray diagram of reflecting type telescope. State its magnifying power.

(c) State the advantages of reflecting type telescope over the refracting type.​

Answer 1

Answer:

state the advantages of reflect

Explanation:

ing type telescop.state it's magnifying power.

Answer 2

Astronomical telescope

Explanation:

• Consideration for choosing the objective of the telescope includes

1. The large focal length in order to get greater magnifying power.
2. The large aperture that increases light-gathering power and thus more light rays enter through the aperture providing the viewer distinct vision with efficient resolving power.

• Advantages of reflecting telescope include the absence of chromatic aberration thus allow all colours to focus efficiently, easy and cost-efficient to build than refracting type.
• The ray diagram is shown below,