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
To determine the outcome of replacing one yellow light source with two violet light sources, we need to consider the concept of the photoelectric effect.
The photoelectric effect states that when photons, which are packets of light energy, strike a metal surface, they can cause the emission of electrons from the surface. The energy of the photons should be greater than the work function of the metal (minimum energy required to remove an electron from the metal surface) for electrons to be emitted.
In this scenario, we have a metallic surface that emits electrons when irradiated with a yellow light source of power 25 Watts. If we replace this yellow light source with two violet light sources of the same power, we need to analyze the effect on the emission of electrons.
When two violet light sources are used, each source will emit photons with a higher energy compared to the yellow light source. In other words, the violet light has a shorter wavelength and higher frequency than yellow light. Since the energy of photons is directly proportional to the frequency (E = hf, where E is the energy, h is Planck's constant, and f is the frequency), the violet light sources will provide photons with more energy.
As a result, when the metallic surface is irradiated with the higher-energy violet light photons, there will be an increased probability of electrons being emitted from the surface. Therefore, the number of emissions of electrons will increase when one yellow light source is replaced by two violet light sources of the same power.
However, it is important to note that the maximum velocity of the emitted electrons remains the same. The maximum velocity depends on the energy of the emitted electrons, which is determined by the energy of the incident photons. Since the two violet light sources have the same power as the yellow light source, the energy of the incident photons (and hence the maximum velocity of the emitted electrons) will not change.
Therefore, the correct answer is: The number of emissions of electrons will increase, but the maximum velocity remains the same (option A).