Photoelectric Effect (7 of 8) Determining Planck's Constant

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The photoelectric effect is the emission of electrons when light is shined on a material. Electrons emitted in this way can be called photoelectrons.

In 1905, Albert Einstein published a paper advancing the hypothesis that light energy is carried in discrete quantized packets to explain experimental data from the photoelectric effect. This was a key step in the development of quantum mechanics. In 1914, Millikan's experiment supported Einstein's model of the photoelectric effect. Einstein was awarded the Nobel Prize in 1921 for his discovery of the law of the photoelectric effect.

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Alot of people already commented how grateful they are for your videos and I cant just write my final physics tomorrow without telling you how grateful I'm I watched all of your videos including this one and you helped me understand the concept much more under 2 or 3 hours

Wish me good luck for Tomorrow's paper. Hopefully this time I would achieve a distinction

brayton

Your presentation is strong and easy to understand.

detrojadhruv

Your ideas are backed by strong, nice and intuitive basics very well.

fahimahmedbhuiyan

YOU SAVED ME! Sadly i can only give you my ''like'' and ''subscribe''

jeffreydaclan

Where did these numbers come from? Are the values just a numerical example, a sort of "fake data", or were they actually experimentally obtained, and using what photocell? The closest Wo value to 2.05E -19 is for Cs (accepted value of 2.1E-19), but this would be a rather special photocell. Normally, you would expect a Leybold-style potassium photocell to be used in an undergraduate lab, and Wo for potassium is 2.3E-19, while the fit error to the values quoted is tiny. By the way, I get a 2.06E-19+/-0.01E-19 J from your data (not 2.05), probably because you use a rather truncated value for the charge of the electron. I know it might appear I am nitpicking, but I am genuinely curious as to how your rather perfect-looking data was obtained. Thanks!

SimplyTheDoctor

This helped me a lot! Thanks! :) the tempo is perfect

marit

Great video and good explaining! There's just one thing I dont get, when calculating planck's constant you say you get 6.63E-34, but when I put in your numbers I get -4.06E+14. Why is that? I've done it plenty of times and still get the same answer.

majawilliams

shouldn't the left side be positive and right side negative starting 4:46, just personal opinion, I might be wrong tho

diankuizhang

I am having U value as negative then what will be value of ev .
Ex -I have U value =-0.99 then what will be the value of ev

akshatbohra

Hello Sir. Great video. If I'm asked a question like work out work function of a metal from the threshold frequeuncy of the graph, am I meant to use the gradient of the graph as the value for plancks constant?

alialmeerahmed