A convex lens 'A' of focal length 20 cm and a concave lens 'B' of focal length 56 cm are kept along the same axis with the distance 'd' between them. If a parallel beam of light falling on A leaves B as a parallel beam, then the magnitude of distance d (in cm) is: - VgyanHub

Question:

A convex lens ‘A’ of focal length 20 cm and a concave lens ‘B’ of focal length 56 cm are kept along the same axis with the distance ‘d’ between them. If a parallel beam of light falling on A leaves B as a parallel beam, then the magnitude of distance d (in cm) is:

Options :

(a) 30
(b) 25
(c) 50
(d) 36

Answer :

(d) 36

Answer Steps :

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