Question

an object of height 4cm is kept at a distance of 30cm from a concave lens use the lens formula to determine the image distance, nature and size of the image formed it focal length of the lend is 15cm​

Answer 1

Answer:

Explanation:

We have,

h = 4 cm

u = -30 cm [distance of object]

f = -15 cm [Focal lenght of a concave lens is taken as negative]

Lens formula,

1/v-1/u=1/f

1/v=1/f+1/u

1/v=[1/-15]+[1/-30]

1/v=-30-15/450

1/v=-45/450

v=450/-45

v=-10

Hence, the distance of image is -10 cm.

It means that the image formed is virtual and erect.

Maginification=v/u

m=-10/-30

m=1/3

m=0.33

The image is one-third of the size of the object.