09070.00 Millikan Oil Drop Experiment

The oil drop experiment designed by Robert A. Millikan, gives a very direct and graphic measurement of the charge on the electron. This compact version of the apparatus lets the student reproduce this important demonstration of the quantum nature of electric charge as well as determine the value of the elementary charge.

The oil droplets introduced with an atomizer into the capacitor chamber are illuminated by an internal halogen lamp which is strong enough for video or visual observation. A measuring microscope with an eyepiece micrometer is used to observe the droplets. The oil drops are viewed with a 100X microscope.

• Droplet motion with and without the electric field
• Falling and rising velocity with constant electric field voltage
• Change of charge on a droplet due to external radioactive source