A diverging lens has a focal length of 20cm, at what distance should an object of height 4cm from the optical centre of lens be placed so that it's image is formed 10cm away from the lens.Find the size of the image and draw the ray diagram to show the formation of the image
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f = -20cm, v = -10cm, h = 4cm
1/v - 1/u = 1/f
1/u = 1/v - 1/f
1/u = -1/10 + 1/20 = -1/20
u = - 20cm = object distance
h'/h = v/u
h'/4 = -10/-20
h'/4 = 1/2.
h' = 2cm = image height.
1/v - 1/u = 1/f
1/u = 1/v - 1/f
1/u = -1/10 + 1/20 = -1/20
u = - 20cm = object distance
h'/h = v/u
h'/4 = -10/-20
h'/4 = 1/2.
h' = 2cm = image height.
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