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The lens of a slide projector focuses on an image of height 1.5m on a screen placed 9.0 m from the projector. If the height...

The lens of a slide projector focuses on an image of height 1.5m on a screen placed 9.0 m from the projector. If the height of the picture on the slide was 6.5 cm, determine, (a) Distance from the slide (picture) to the lens (b) Focal length of the lens

Answers

Magnification = height of the image / height of the object = v / u = 150 / 6.5 = 900 / u u = 39 cm (distance from slide to the lens). m = 23.09
1 / f = 1 / u + 1 / v = 1 /39 + 1 / 90 = 0.02564 + 0.00111 1 / f = 0.02675 (reciprocal tables)
f = 37.4 cm

Mutiso answered the question on October 15, 2018 at 18:04

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