# Calculating Charge Of Electron (Millikan Oil Drop Experiment

• Manav
In summary, the conversation involves a discussion of the Milikan Oil Drop Experiment being conducted through a simulation on a specific website. The experiment involves calculating the charge of an electron using data such as oil density, air viscosity, and distance. The formula used for the calculation is q = (6πηr(v1 + v2)d) / V. The participant also shares a spreadsheet of their data and discusses the issue of their charge values being too large. There is a suggestion to find a common divisor for the observed charges.
Manav

## Homework Statement

I was doing the Milikan Oil Drop Experiment from a simulation this site: http://scienceclub.ucoz.com/index/0-109. I tried calculating the charge of the electron but it was from the real value.

Oil Density: 920 (kg/m^3)
Viscosity of Air: 1.81×10−5 kg/(m*s)
Distance: 0.0025 m

## Homework Equations

q = (6πηr(v1 + v2)d) / V
η = viscosity of air
v1 = terminal velocity
v2 = velocity of oil drop with x-ray on
d = Distance
V = Balancing Voltage

## The Attempt at a Solution

Here the data that I took regarding the experiment. Please don't edit anything. I allowed permission to edit so you can see the automation I had done on it. https://docs.google.com/spreadsheets/d/1Ac_3WuWi14Rfhduq2n_ZEBYI6s-qXRIczJrT46vedyI/edit?usp=sharing

Your times are quite short and I would be interested in how you derived the formula for the charge. Better: Start with a description of what you measured.
All your charge values are way too large, I agree.

You can't take the average (or at least it won't help). The drops will in general have different multiples of the elementary charge on them. You have to find some sort of common divisor of their observed charges (not in the mathematical sense as the measurements are not exact).

## 1. How did Millikan calculate the charge of an electron in the oil drop experiment?

Millikan used a combination of oil drops, an electric field, and gravity to determine the charge of an electron. He measured the velocity of oil drops as they fell through an electric field and used this data to calculate the charge on each individual drop. By comparing the charges of different drops, he was able to determine the charge of a single electron.

## 2. What is the significance of the oil drop experiment in determining the charge of an electron?

The oil drop experiment is significant because it provided the first direct measurement of the charge of an electron. Before this experiment, the charge of an electron was only known through theoretical calculations. Millikan's experiment provided concrete evidence and helped to solidify our understanding of the basic building blocks of matter.

## 3. How accurate was Millikan's calculation of the charge of an electron?

Millikan's original calculation of the charge of an electron was within 1% of the currently accepted value. However, with advancements in technology and more precise measurements, the currently accepted value is even more accurate. Nonetheless, Millikan's experiment was groundbreaking and laid the foundation for future research in this area.

## 4. What challenges did Millikan face during the oil drop experiment?

One of the main challenges Millikan faced was ensuring that the oil drops were completely stationary before taking measurements. Any movement of the drops could greatly affect the results. He also had to account for other factors such as air resistance and the variations in charge on different oil drops. These challenges required careful attention to detail and multiple trials to ensure accurate results.

## 5. How has the oil drop experiment influenced modern science?

The oil drop experiment has had a significant impact on modern science, particularly in the field of subatomic particles. It provided the first direct measurement of the charge of an electron and solidified our understanding of the basic building blocks of matter. The experiment also paved the way for future advancements in technology and further research into the properties of subatomic particles.

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