An astronomical telescope of ten fold an

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Target Exam

CUET

Subject

Physics

Chapter

Ray Optics

Question:

An astronomical telescope of ten fold angular magnification has a length of 44 cm. The focal length of the objective is:

Options:

4 cm

40 cm

440 cm

44 cm

Correct Answer:

40 cm

Explanation:

Magnification is $ M = \frac{f_0}{f_e} = 10$

$ f_0 + f_e = 11f_e = 44cm \Rightarrow f_e = 4cm , f_0 = 40cm$

The correct answer is Option (2) → 40 cm