Question 1: Ray Optics

Question

If focal length of objective and eye lenses are $$10 \mathrm{~cm}$$ and $$10 \mathrm{~mm}$$ respectively and tube length is $$11 \mathrm{~cm}$$ then angular magnification of telescope is

Accepted Answer

Given, Focal length of objective lens, $$f_o=10 \mathrm{~cm}$$
Focal length of eye lens, $$f_e=10 \mathrm{~mm}=1 \mathrm{~cm}$$
Total length $$=f_o+f_e=10+1=11 \mathrm{~cm}$$
This is the case when the final image is formed at infinity, therefore
Angular magnification, $$|m|=\left|\frac{f_o}{f_e}\right|=\frac{10}{1}=10$$

Answer

10

Answer

5

Answer

100

Answer

50

Ray Optics

If focal length of objective and eye lenses are $10 \mathrm{~cm} and 10 \mathrm{~mm} respectively and tube length is 11 \mathrm{~cm}$ then angular magnification of telescope is

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