Answer:
The coarse adjustment knob is for focusing of the slide.
Step-by-step explanation:
Coarse Adjustment Knob- The coarse adjustment knob built on the arm of the microscope is for moving the stage up and down to bring the specimen into focus.
Note:
Fine Adjustment Knob - is inside the coarse adjustment knob and is used for sharp focusing of the specimen under low power and is used for all focusing when high power lenses is used.