Question

focal length of convex lens 2 m power is ___D
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Answer 1

☞. REQUIRED ANSWER :- The given focal length of the concave lens is f = -2 m. It is negative because a concave lens always has a negative focal length. The unit of power is dioptre (D) and 1D = 1m-1. Therefore, the correct answer for the given question is option (D).

HOPEFULLY IT HELPFUL YOU ☑️☑️☑️

Answer 2

$power \: = \frac{1}{focal \: length \: (in \: m)} \\ power = \frac{1}{2} \\ power \: = 0.5 \: dioptre$

there you go :)