What happens if you try to use the coarse adjustment when the 10X lens is in place

The correct answer would be - difficulty in precise focusing and risk of crashing the objective into the slide.

Explanation:

The coarse adjustment knob present on the arm of the light or compound microscope that moves the stage towards up and down to focus on the specimen.

As the partial revolution leads to large vertical movement it is difficult to adjust the focus on high power objective. If the high power objective that is 10X or above while adjusting coarse adjustment, there is a risk to crash the objective on the specimen.

Focus is not clear and low resolution