Question

The lens having power 5D. an object is placed at distance of 30cm. what is the image of object from the lens?​

Answer 1

Answer:

concave lens produces a virtual, erect diminished image.

Using Real Is Positive RIP Convention, u=30 and f=-15

1/u+1/v=1/f

1/30+1/v=−1/15

1/v=−1/15−1/30=−3/30=−1/10

v=−10M=v/u=−1/3

So image is erect, virtual, 1/3 size of object, and 10 cm from the lens, (between lens and object)

Answer 2

Answer:

Image distance =60cm

Explanation:

Given power =5D

P =1/f =5D (f is in meters)

f =1/5m =100/5 cm =20cm

Object distance u =30cm

1/f =1/u +1/v

1/20=1/30 +1/v

1/v =(1/20)- (1/30)

1/v =(3-2)/60 =1/60

Image distance v =60cm