Explain the working of an astronomical telescope using refraction of light. |
---|
→ An astronomical telescope consists of two convex lenses. The lenses are fitted coaxially in a metal tube such that the distance between them can be changed. The focal length and the diameter of the objective lens is greater than the focal length and the diameter of the eyepiece. The objective lens is pointed towards the distant object. Due to its large size, the objective collects maximum amount of light and forms a real, inverted and diminished image. This image acts as an object for the eye piece. The eyepiece is so adjusted that this image falls just within its focal length. The eyepiece acts as a simple microscope and produces the final image. The final image is virtual and highly magnified. Generally, using the same objective lens but different eye pieces, different magnifications can be obtained. 4 Marks |
This page was last modified on
30 July 2019 at 03:18