In the Millikan oil-drop experiment (see Figure 2.5), the tiny oil drops are observed through the viewing lens as rising, stationary, or falling, as shown here. (a) What causes their rate of fall to vary from their rate in the absence of an electric field?

Video transcript

Hi everyone here we have a question telling us. In 1923, Robert A. Millikan received the Nobel Prize in Physics for his oil drop experiment. The experiment included the observation of tiny oil droplets between two electrically charged plates. The oil drops were observed as falling, stationary or rising. The presence of an electric field has an effect of the rate of fall of oil particles. Explain what force or factor would determine the rate of fall of oil drops if the electric field were removed, so if the electric field were removed, the only force we have left to determine the rate of fall is going to be gravity, and that is our final answer. Thank you for watching. Bye.