Draw the ray diagram for a Cassegrain telescope - AQA - A-Level Physics - Question 1 - 2017 - Paper 4

Start with a concave primary mirror, which is typically large and parabolic in shape, positioned in the center of your drawing.

Place a smaller, convex secondary mirror above the primary mirror. Ensure it is positioned slightly above and towards the focal point of the primary mirror. Label both mirrors clearly.

Draw two rays that are initially parallel to the principal axis. These rays should come from a distant object and head towards the primary mirror.

When the rays hit the primary mirror, they will reflect towards the secondary mirror. Make sure the rays reflect off the mirror correctly, converging towards the secondary mirror.

The secondary mirror will reflect the rays further towards the eyepiece. Indicate this direction clearly in your diagram.

To represent the eyepiece, draw a line at the focal point of the secondary mirror where the reflected rays converge. Label this as the eyepiece location.

Ensure that the rays are drawn straight and clearly show their paths from the object, through the mirrors, and into the eyepiece.