Question
Question: An astronomical telescope in normal adjustment receives light from a distant source S. The tube leng...
An astronomical telescope in normal adjustment receives light from a distant source S. The tube length is now decreased slightly –
A
Virtual image of S will be formed at a finite distance
B
O image will be formed
C
Small, real image of S will be formed behind the eyepiece, close to it
D
Large, real image of S will be formed behind the eyepiece, far away from it`
Answer
Virtual image of S will be formed at a finite distance
Explanation
Solution
When tube length is increased, the (real) intermediate image formed by the objective will lie beyond the focus of eyepiece. This will produce a real, magnified image behind the eyepiece.