kumar is producing the photoelectric effect by using red light. he wants to increase the energy of emitted…
kumar is producing the photoelectric effect by using red light. he wants to increase the energy of emitted electrons. based on the research of albert einstein, what is the best way for him to do this?\no increase the intensity of red light.\no decrease the intensity of red light.\no use a different colored light that has a higher frequency.\no use a different colored light that has a lower frequency.
Answer
Explanation:
Step1: Recall photoelectric - effect principle
The energy of emitted electrons in the photoelectric effect is given by $E = h\nu-\varphi$, where $h$ is Planck's constant, $\nu$ is the frequency of the incident light, and $\varphi$ is the work - function of the metal. The energy of emitted electrons depends on the frequency of the incident light, not its intensity.
Step2: Analyze each option
- Increasing the intensity of red light only increases the number of photons, not the energy of each photon and thus not the energy of emitted electrons.
- Decreasing the intensity of red light also does not affect the energy of emitted electrons, just the number of photons.
- Using a different colored light with a higher frequency will increase the energy of the incident photons, and according to the photoelectric - effect equation, will increase the energy of the emitted electrons.
- Using a different colored light with a lower frequency will decrease the energy of the incident photons and thus decrease the energy of the emitted electrons.
Answer:
Use a different colored light that has a higher frequency.