Question

The power of a lens is-0.5d.what is the Focal We length and nature of lense will be

Answer 1

Power of The Lens = -0.5 D

Power of a lens = 100/f(cm)

100/f=-1/2

f=-200cm

Since the Focal Length is Negative, its a Concave Lens

Answer 2

Answer of your Question is :

Focal length ( f ) = - 2 m

Nature of lens used :

CONCAVE LENS

also known as DIVERGING LENS .

Concave lens have NEGATIVE Focal Length .

Hope it helps !!!