# If a spherical lens has a power of, −0.25 D, the focal length of this lens will be : (a) −4 cm (b) −400 mm (c) −4 m (d) −40 cm - Science

If a spherical lens has a power of, −0.25 D, the focal length of this lens will be :
(a) −4 cm
(b) −400 mm
(c) −4 m
(d) −40 cm

#### Solution

-4 m

Focal length =1/"power"=1/0.25=-100/25=-4m

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#### APPEARS IN

Lakhmir Singh Class 10 Physics (Science)
Chapter 5 Refraction of Light
Q 35 | Page 262