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# Photon/Intensity watch

1. Does a higher intensity of light from a light source mean (a) an increased number of photons being emitted or (b) the original number of photons emitted have a higher energy? I don't think it's (b) because the energy of a photon depends on its frequency/wavelength, and by increasing the intensity of light, it does not affect its frequency nor wavelength. But just to get some clarification, is it (a) or another reason?
Thanks
2. (Original post by anamariamikhail)
Does a higher intensity of light from a light source mean (a) an increased number of photons being emitted or (b) the original number of photons emitted have a higher energy? I don't think it's (b) because the energy of a photon depends on its frequency/wavelength, and by increasing the intensity of light, it does not affect its frequency nor wavelength. But just to get some clarification, is it (a) or another reason?
Thanks

Without going into the actual measurement of light intensity (I don't know it but I know it roughly and that it's pretty weird), light intensity is photons per second per unit area. If light intensity increases, you have more photons per second per unit area so that implies an increased amount of photons are emitted, hence a.
3. (Original post by Duskstar)

Without going into the actual measurement of light intensity (I don't know it but I know it roughly and that it's pretty weird), light intensity is photons per second per unit area. If light intensity increases, you have more photons per second per unit area so that implies an increased amount of photons are emitted, hence a.
Right okay I get that - Just another relevant question: If you increase the light intensity onto a semi-conductor material, are the atoms within the material affected by the thermal energy increase associated with the increase in intensity, and do they vibrate more? Or is light intensity not related to thermal energy at all and I'm making this all up haha
Thanks
4. (Original post by anamariamikhail)
Right okay I get that - Just another relevant question: If you increase the light intensity onto a semi-conductor material, are the atoms within the material affected by the thermal energy increase associated with the increase in intensity, and do they vibrate more? Or is light intensity not related to thermal energy at all and I'm making this all up haha
Thanks
I haven't covered that, but I would assume so. Increasing the intensity of light will increase the rate at which energy is delivered, so that sounds correct. Don't quote me on this though - I've not studied that yet lol.
5. (Original post by Duskstar)
I haven't covered that, but I would assume so. Increasing the intensity of light will increase the rate at which energy is delivered, so that sounds correct. Don't quote me on this though - I've not studied that yet lol.
Tbh I do IB HL Physics and this isn't on the course, I just need this little bit of info to go a little bit further in order to develop my hypothesis for my IA. Thanks for the help though

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