Photoelectric Effect 4

What is the effect of: on the Photoelectric effect?

INTENSITY (brightness, power)

The following diagram shows a dim light of frequency f being used to perform the photoelectric effect.



Question:
What would happen if the light was made brighter, with the same frequency f?

There would be MORE electrons released since there would be more beams of light.



But the kinetic energies of each electron would remain unchanged
It is important to note that if this was a solar cell, more current would flow due to the increased number of electrons, i.e. the brighter light increases the current strength due to the increase in the number of electrons.

In other words :
Brighter light:


FREQUENCY

The following diagram shows a light of frequency f being used to perform the photoelectric effect.



Question:
What would happen if the frequency was increased? (Not the intensity.)




The photons would now have greater energy (140J). But since the work function of the metal is still the same, the kinetic energy of the photoelectrons would increase (60J).
(But the same number of electrons would be ejected since the photon was not made brighter.)

In other words:
Higher frequency light:




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