Question

What is the physical diameter of the first optical element in the telescope?

(a) Optical aperture

(b) Field of view

(c) Effective focal length

(d) Light detector

I got this question in a national level competition.

This key question is from Stellar Sensor Design in division Celestial Navigation, Doppler and Altimeter Radars of Avionics

Answer 1

Correct choice is (a) Optical aperture

To explain I would say: Each design of a telescope is characterized by an optical aperture, an effective focal length, and a field of view. The optical aperture is the physical diameter of the first element in the telescope.