A metallic surface emits electrons when it is irradiated with a yellow light source of power 25 Watts. What happens to the emission of the electrons if one yellow light source is replaced by two violet light sources of same power?
The number of emission of electrons will increase but the maximum velocity remains the same.
The number of emission of electrons will decrease but the maximum velocity remains the same.
Both the number of emission of electrons and the maximum velocity will decrease.
Both the number of emission of electrons and the maximum velocity will increase.
I think A
Both the number of emission of electrons and the maximum velocity will increase.
You are correct. The emission of electrons will increase when one yellow light source is replaced by two violet light sources of the same power. This is because violet light has a higher frequency and energy compared to yellow light. The higher energy of the violet light leads to more electrons being emitted from the metallic surface through the photoelectric effect. However, the maximum velocity of the emitted electrons remains the same, as this is determined by the energy of the photons, not the number of light sources. So, the correct answer is option A: The number of emission of electrons will increase, but the maximum velocity remains the same.
To determine the answer, we need to understand the phenomenon of photoelectric emission and how it is affected by different light sources.
The phenomenon of photoelectric emission states that when light, known as incident light, shines on a metallic surface, it can cause the ejection of electrons from the surface. The energy of the incident light must exceed the minimum energy required, known as the threshold energy, for electrons to be emitted.
In this case, we are comparing a yellow light source with two violet light sources, both having the same power. Power is the rate at which energy is transferred or converted, and it is measured in watts.
When we compare the yellow light source and the violet light sources, we find that they emit light of different wavelengths. Yellow light has a longer wavelength than violet light. Now, the energy of a photon is inversely proportional to its wavelength. This means that the shorter the wavelength (violet light), the higher the energy of the photon.
Since the violet light sources have a shorter wavelength than the yellow light source, they have higher energy photons. Therefore, the violet light sources will have photons with energy greater than or equal to the threshold energy required for the emission of electrons from the metallic surface.
Based on this information, we can conclude that the number of emitted electrons will increase when the yellow light source is replaced by two violet light sources of the same power. This is because the higher energy photons from the violet light sources will have sufficient energy to eject more electrons from the metallic surface.
However, the maximum velocity of the emitted electrons will remain the same. The maximum velocity of the emitted electrons primarily depends on the work function of the material and is independent of the frequency or energy of the incident light.
Therefore, the correct answer to the question is: The number of emission of electrons will increase, but the maximum velocity remains the same.