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.#