Question:
Based on Millikan's Oil Drop Experiment, what can you conclude about the existence of a smallest unit of electric charge, of which other charges are multiples? Include a diagram of Millikan's original apparatus.
So i found lots of great websites, so please don't google Millikan and post a webpage. Here's a simplistic version of what I've got:
Description of the experiment...As more and more trials were done, it became evident that all of the droplets contained charges that were multiples of a smallest value. Millikan correctly concluded that this must be the value on an electron, and therefore the value of the elementary charge, 1.602 × 10-19 C.
Any other things I can add about his conclusion?
Thankyou.Rach.
Your description pretty much says it all, as far as the conclusion is concerned, and how it was arrived at. What he measured was the field necessary to keep the oil drops suspended between parallel plates. When it was motionless, the electric force, F = Q E, equaled the weight. He also had to figure out the weight of the drop, which he obtained from a fluid mechanical formula (Stokes' Law) by measuring the terminal velcoity as it fell.
Stokes' law is actually an approximation; a better version is called Oseen's Law
Millikan's Oil Drop Experiment is a crucial experiment in understanding the existence of a smallest unit of electric charge, which is the elementary charge. Here are some additional points to add about Millikan's conclusion:
1. The experiment involved observing tiny oil droplets suspended in a chamber between two electrically charged plates. By carefully adjusting the electric field strength, Millikan was able to measure the motion of the droplets.
2. By balancing the gravitational force acting on the droplets with the electrostatic force, Millikan determined the charge on individual droplets. He observed that the charges were always found to be multiples of a specific value.
3. This specific value was determined to be the elementary charge, which is the charge carried by a single electron. Millikan concluded that the existence of a smallest unit of electric charge was supported by his experimental results.
4. The value of the elementary charge determined by Millikan through this experiment was found to be 1.602 × 10-19 Coulombs, which is now a well-accepted constant in physics.
5. Millikan's oil drop experiment provided experimental evidence for the quantization of electric charge, supporting the concept that the charge of any object is always made up of an integral multiple of the elementary charge.
6. This experiment laid the foundation for understanding the structure of matter and the significance of the fundamental property of electric charge, which is crucial in various fields including electromagnetism, atomic physics, and particle physics.
Regarding a diagram of Millikan's original apparatus, I apologize for the limitations of this text-based platform, which prevents me from providing visual diagrams. However, a quick internet search will yield numerous detailed diagrams of Millikan's original setup, which will provide you with a clearer understanding of the experiment.
Millikan's Oil Drop Experiment is a famous experiment conducted by physicist Robert Millikan in 1909 to determine the charge of an electron. The experiment involved suspending tiny oil droplets in a chamber between two charged plates, as shown in the diagram below:
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Air Chamber
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Oil droplet
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Initially, the plates were given a known charge, causing the oil droplets to either rise or fall due to the electric field created. By adjusting the voltage on the plates, Millikan was able to carefully balance the electric force on the droplets with the gravitational force, causing them to remain suspended. This allowed him to measure the charge on each oil droplet.
During the experiment, Millikan observed that the charges on the droplets were all multiples of a certain smallest value, suggesting that all charges are quantized in units of this smallest charge. He concluded that this smallest charge must be the charge of a single electron, which he then determined to be 1.602 × 10^(-19) coulombs (C).
In addition to the conclusion about the existence of a smallest unit of electric charge, Millikan's experiment also provided evidence for the quantized nature of electric charge, which further supported the atomic theory and the existence of discrete particles like electrons.
It is important to note that while Millikan's experiment determined the charge of an electron, it did not directly prove the existence of other subatomic particles like protons and neutrons. However, later experiments and discoveries in nuclear physics confirmed the existence of these particles with their respective charges, leading to the development of the atomic model as we know it today.