OIL DROP EXPERIMENT Meaning and
Definition
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The oil drop experiment, also known as Millikan's oil drop experiment, is a fundamental physics experiment conducted to measure the electrical charge carried by an individual electron. It was first performed by the American physicist Robert A. Millikan in 1909.
The experiment involves observing tiny charged oil droplets suspended in a chamber and subject to gravity and an electric field. By carefully adjusting the electric field strength, Millikan was able to balance the gravitational force acting on the oil droplets. This achieved a state of equilibrium where the motion of the droplets remained constant.
Using this setup, Millikan measured the terminal velocity of the oil droplets falling under the influence of gravity alone and then when subjected to both gravity and the applied electric field. By precisely calculating the velocity of the droplets under each condition, he was able to determine the relationship between the charge on the oil droplet and the strength of the electric field required to achieve equilibrium.
Through numerous repetitions of the experiment, Millikan obtained a series of charge values that were all multiples of a fundamental unit of charge. Combining his findings with the electron mass obtained from other experiments, he was able to calculate the value of the elementary charge with remarkable accuracy.
The oil drop experiment played a crucial role in determining the charge of an electron, which has become an essential constant in modern physics.
