Question

7. a object is placed at a distance of 30 cm from a
a lens of focal length 20 cm.
a.Find the position of the image.
b.the image real or virtual?
c.the image erect or inverted?​

Answer 1

Answer:

Explanation:

A) 1/f=1/v-1/u

1/20=1/30-1/u

1/20+1/30=1/u

3-2/60=1/u

1/60=1/u

u= ‐60

B)

apply magnification formula:

*************************************************

m=v/u

m=30/-60

m=1/-2

=>m=0.5

Therefore the image is real

C)

The image is real and invert