Question

An object and its image are as shown in the diagram below. If the object image distance is 4 cm and the magnification is 3, a)Find the ratio u:v:f.b)What is the type of the lens used

Answer 1

Explanation:

u=-4(according to sign convention)

magnification=-v/u

3=-v/-4

v=12

lens formula=1/f=1/v-1/u

1/f=1/12-1/-4

1/f=1-3/12

1/f=-2/12

1/f=-1/6

f=-6

ratios=u:v:f=4:12:6=2:6:3

concave lens is used