Correct Answer : Catadioptric
Explanation : Telescopes are of three types: refractive, which uses lenses as their primary focusing elements, reflective, which uses a curved mirror for focusing, and catadioptric, which mix mirror and lens systems.
Correct Answer : Option (D) : Optical transmission losses
Explanation : For anti-reflection coated optics, the optical transmission losses may be 1% or 2% at each air to glass or glass to air optical control surface within the telescope, including windows or sensor covers or surfaces. For uncoated optics, the loss per surface is about 4% to 5%.
Correct Answer : Option (B) : f/ number
Explanation : The ratio of focal length to aperture is called the f/ number. For example, an f/10 telescope may have a 30 in. focal length and a 3 in. aperture.
Correct Answer : Option (C) : Angular size of image
