Milikan's oil drop experiment

• Milikan's oil drop experiment

  A) positively charged plate

  B) negatively charged plate

  C) electrostatic force or upthrust

  D) weight or air resistance

  E) negatively charged oil drops

  
• some droplets remain stationary as the weight and the electrostatic force are equal
• some droplets drifted slowly through the apparatus, allowing Milikan to find out the charge which was quantised - the charge on the droplets were all multiples of the elementary charge