Question

2. Two lenses of power 20 D and -10 D are in contact with each other. The focal length of combination is:
(B) -10 cm
(D) -20 cm
(A) 10 cm
(C) 20 cm​

Answer 1

Answer:

please answer my question

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Answer 2

Answer:

20cm

Explanation:

e (C) at a distance 30cm from plane surface ( D) at a distance 20cm from ... 20cm 10cm AGFOR Radius of curvature=20cm radi (A) On plane surface ( B) at ...