Question

Which liquid is used in oil drop experiment and why?

Answer 1

J.J. Thomson had used water droplets in his earlier experiments, so that was their first attempt. But the heat of the light source caused the small droplets to evaporate within about two seconds. Millikan and Fletcher discussed possible other liquids such as mercury, glycerine, and oil.

hope this helps you (◕ᴗ◕✿)