Question

A lens of focal length 20cm is used to produce a ten times magnified image of a film slide on a screen. How far must the slide be placed from the lens?

*I need the diagram*
*Please give me the diagram with proper measure*

{The one who give me the correct diagram I will mark him brilliant and I will report the one who give me the wrong answer}​

Answer 1

Answer:

f = 20 cm

m = - 10

u =?

m = v/u = -10

v = -10u

Lens formula: 1/v – 1/u = 1/f

1/-10u – 1/u = 1/20

(-1 – 10)/10u = 1/20

-11/10u = 1/20

u = -22 cm

v = -10 × -22 = 220 cm