Question

multiple - choice question
under which objective lens is the coarse adjustment knob used?
it can be used for all three objective lenses
low power and medium power objective lenses only
low power objective lens only

Explanation:

The coarse - adjustment knob is used to quickly bring the specimen into focus. It is used with low - power and medium - power objective lenses. Using it with high - power objective lenses can damage the lens or the specimen as it moves the stage up and down by a relatively large amount.

Answer:

B. low power and medium power objective lenses only