Question

if a power of a lens is + 2D what is the focal length and its nature​

Answer 1

Explanation:

Power = 2d

Focal length = 1/p

= 1/2 m = 100/2 cm

The lens is convex lens as focal length is positive

If u = -10 cm

f = 50 cm

1/f = 1/v - 1/u

1/50 = 1/v - 1/(-10)

1/50 = 1/v + 1/10

1/50 - 1/10 = 1/v

(1 - 5)/50 = 1/v

1/v = -4/50

v = -50/4 cm

As v is negative the image will form on the same side of object so nature of image is virtual and erect.