COMEDK · Physics · 25. Ray Optics
A telescope has an objective of focal length 60 cm and eyepiece of focal length 5 cm. The telescope is focussed for least distance of distinct vision for an object 300 cm away. The linear magnification produced by the telescope is:
- A \(-\)1.5
- B \(-\)2
- C 1.5
- D 2
Answer & Solution
Correct Answer
(A) \(-\)1.5
Step-by-step Solution
Detailed explanation
For objective lens: \(f_o = 60\) cm, \(u_o = -300\) cm \(\dfrac{1}{v_o} = \dfrac{1}{f_o} + \dfrac{1}{u_o} = \dfrac{1}{60} - \dfrac{1}{300} = \dfrac{4}{300}\) \(v_o = 75\) cm \(m_o = \dfrac{v_o}{u_o} = \dfrac{75}{-300} = -\dfrac{1}{4}\) For eyepiece: \(f_e = 5\) cm, image at…
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