# (I) Express Power of a Concave Lens of Focal Length 50 Cm with Its Sign. - Physics

Numerical

Express power of a concave lens of focal length 50 cm with its sign.

#### Solution

Power = 1/"focal length (in metres)"

Now, a concave lens has a virtual focal length ; \ f = -50 cm

Power = 100/-50 = -2D

Powerof a concave lens is negative and the power is -2D.

Concept: Concave Lens
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#### APPEARS IN

Frank ICSE Class 10 Physics Part 2
Chapter 2 Light
Exercise 2.2 | Q 2.1 | Page 103