Question

The focal length of a simple magnifier is 8.50cm. Assume the magnifier to be a thin lens placed very close to the eye.

How far in front of the magnifier should an object be placed if the image is formed at the observer's near point, 25.0cm in front of her eye?

If the object is h=1.30 mm high, what is the height of its image formed by the magnifier?

Answer 1

Part A)

1/f = 1/p + 1/q

1/8.5 = 1/p + 1/-25

p = 6.34 cm away from the lens

Part B)

h'/h = -q/p

h'/1.3 = -(-25)/6.34

h' = 5.12 mm