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Two lenses of power +12 and -2 dioptres ...

Two lenses of power `+12` and `-2` dioptres are placed in contact. The combined focal length of the combination will be

A

10 cm

B

12.5 cm

C

16.6 cm

D

8.33 cm

Text Solution

Verified by Experts

The correct Answer is:
A
`P_(eq) = P_(1) + P_(2) = 12 - 2 = 10 D `
`:. f = (1)/(P) = (1)/(10) = 0.1 m = f = 10 cm `
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