The image of a microchip in a projection microscope measures 8 inches by 10 inches. The width of the actual chip is 4 millimeters. How long is the chip?

1 Answer
Jan 25, 2016

5 mm.

Explanation:

The image of a projection microscope keeps the original ratio:
k="width"/"length"

As the width is assumed smaller than the length we have:
k=w/l=w_0/l_o"
k=(8 cancel("in."))/(10 cancel("in."))=(4mm.)/l_o
k=4/5=(4mm.)/l_o => l_o=5/cancel(4)*cancel(4)mm. => l_o=5mm.