Millikan's oil drop experiment - help

[jaderberg]

Im doing millikan's oil drop experiment as my A level physics coursework to eventually calculate the electronic charge. I am fine with all the theory but what I am really struggling with is the actual practical experiment.

I have seen the oil drops a lot and have managed to manipulate them using a voltage however now when I've come back to the experiment after the weekend i can't see anything and if i do see something its just a really faint cloud of oil drops where i can't pick out a single one to analyse. Why is it so temperamental?

Also i got some initial results for oil drops (which came out to be about 2micrometers radius) under a voltage of around 200v but the charge was far too high (approximate to 100-200 electrons). I hooked up the apparatus to a higher voltage and tried to take some results (at about 1000-2000V) but didnt get much...are all my oil drops too highly charged? I really want to isolate and analyse some which only have a few electrons on them but this seems impossible. Would removing the rubber end of the atomiser stop the oil drops from being so highly charged?

Any help would be really appreciated as well as any practical tips for the experiment (i only have 4 hours left!)

Thanks

 

[Nate810]

in advance!One of the most important practical tips is to make sure that you have a good vacuum on your apparatus. This will help ensure that the oil drops remain suspended in the air and are easier to observe. Additionally, it's important to ensure that your voltage is regulated and consistent throughout the experiment, as this will help ensure that you don't end up with overly charged oil drops. Finally, if you're having trouble finding individual oil drops, try using a light source to illuminate them and make them easier to see. You can also reduce the background lighting in the room to make them easier to spot.

 

[ogb p]

for reaching out for help with your Millikan's oil drop experiment. This experiment can be challenging, but it is also very rewarding when you finally get the results you are looking for. It sounds like you have a good understanding of the theory behind the experiment, which is a great start.

Firstly, it is important to note that this experiment is very sensitive and requires a lot of patience and precision. It is not uncommon to have difficulties with the practical aspect, especially when first starting out. The oil drops can be very temperamental and can be affected by factors such as air currents, dust particles, and temperature changes. It is important to try to minimize these factors as much as possible by working in a clean and still environment.

One possible reason for not being able to see the oil drops clearly could be due to the voltage being too high. This can cause the oil drops to be highly charged and repel each other, making it difficult to see a single drop. It is important to find the right balance between the voltage and the size of the oil drops. You may need to adjust the voltage or try using smaller drops to get better results.

Removing the rubber end of the atomizer can help to reduce the charge on the oil drops, but it may also affect the size and stability of the drops. It would be best to try it out and see if it helps in your particular experiment.

In terms of practical tips, make sure to carefully clean and dry all of your equipment before starting the experiment. This will help to reduce any potential sources of error. Also, make sure to take multiple measurements for each oil drop to ensure accuracy and consistency in your results.

I hope these tips help you in your experiment. Don't get discouraged if you encounter difficulties, just keep trying and adjusting your methods until you get the results you need. Good luck!