Question

In the design of telescope, hyperbolic mirror is placed at ___________

• A. foal point of concave parabolic mirror
• B. at a distance of $a^{2}e$ from focal point of concave parabolic mirror
• C. foal point of elliptical mirror
• D. None

Answer 1

The correct option is A foal point of concave parabolic mirror

A concave parabolic reflector will reflect all incoming light rays parallel to its axis of symmetry to a single point, the focus.

So, the concave parabolic mirror is placed behind the hyperbolic mirror at the focal point.