The Photoelectric Effect

This is a demonstration of the photoelectric effect. In the photoelectric effect, electrons are emitted from a metal when light is shone on it, providing that the photon energy is greater than the workfunction of the metal (i.e., the amount of energy needed to rip an electron away from its atom).

This demo is really fussy about humidity, so it often doesn't work, and the video is a cut from more than one take due to some misbehaviour with the experiment. But still, it worked better than it often does.

Video posted for use under Creative Commons Licence - by-nc-sa

Category:

Science & Technology

Tags:

• physics demonstrations
• UNSWTV

[Dartheomus]

Interesting, but I think that all you've managed to demonstrate is that your UV lamp is properly grounded. You built up a charge, and then you held a light over it. NOTHING happened until you touched the light housing to the plate, and hey look, your charge went through your light. That happened both times. Conveniently, when you demonstrated the positive charge not being affected by the light, you got the housing close, but you didn't touch it. I'd like to see the experiment done properly.

[micolich]

@Dartheomus Light housing isn't connected to ground, but I agree it does make it a bit less than convincing in the video. The problem is finding a day when I have time to film and the humidity is low, not the easiest in Sydney. Stay tuned, I'll do it eventually.

[nogimmickcardtrick]

Thank alot! This was simple enough to understand. This really helped.

[melancholytrees]

Thank you so much! I'm currently studying for my ib exams and this cleared things up entirely!

[RafidHoda]

Great demonstration and very well explained! Thanks!

[PakiJuliet6]

this helped me alot... i might just pass my radiation protection test! thanks

[slntdan]

Good explanation. I watched 3 others videos and still couldn't get it until I watched yours. Thanks.

[fnosofd]

helpful, cheers mate.

[80amnesia]

nice experiment man

[pichkari8636]

THIS IS BRILLIANT

I THINK I'LL SHOW THIS VIDEO FOR MY PRESENTATION ON EVOLUTION OF QUANTUM PHYSICS

thanks a ton!!!!