Q130 / 270 · NDA 2012 (Phase 1) · General Ability

Two thin lenses of focal lengths 20 cm and 25 cm are placed in contact. The effection power of the combination is:

A
45 dioptres
Correct answer
B
9 dioptres
C
$\frac{1}{9}$ dioptres
D
6 dioptres

Solution

The correct answer is option B.

Hence, the correct answer is option: 'B'.

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