Question

The above image is that of a reflecting telescope. Reflecting telescopes revolutionised our ways of looking into the sky. They employ mirrors to gather and focus light rather than relying solely on lenses as in their refracting counterparts. These telescopes utilise precisely shaped and polished mirrors to capture incoming light and reflect it to a focal point, where it forms an image for observation.

1. What kind of image of the star is seen by the observer at the eyepiece?
2. What kind of mirror is used in this reflecting telescope?
3. Explain with reason what kind of optical device (type of lens or mirror) that is used at the eyepiece.
   OR
4. What is the role of the plane mirror in the telescope?

Answer 1

1. Real Image (the final image is formed by the lens at the eyepiece).
2. Concave Mirror.
3. A converging lens is used at the eyepiece to collect the rays from the plane mirror and help the viewer to see a real, erect image of the star.
   OR
4. The plane mirror laterally inverts the image formed by the curved mirror, and its position helps direct the rays towards the eyepiece.