Physics 2013 JAMB Past Questions - Question 47: In photo emission ,the number of photo electron ejected per second depends on the

Correct Answer

D

Explanation

In a photo emission, the number of photoelectrons ejected per second depends on the intensity of the incident radiation (or beam)
In photoemission, the number of photoelectrons ejected per second depends on several factors. The main factors that influence the number of photoelectrons ejected are:

1. Intensity of incident light: The number of photoelectrons ejected is directly proportional to the intensity of the incident light. Higher intensity light will result in a greater number of photoelectrons being ejected.

2. Frequency (or energy) of incident light: The energy of the incident light determines the kinetic energy of the photoelectrons. According to the photoelectric effect, only photons with energy greater than the work function of the material can eject electrons. Increasing the frequency (or energy) of the incident light will result in more energetic photons, which can eject more photoelectrons.

3. Work function of the material: The work function is the minimum energy required to remove an electron from the material. Different materials have different work functions. If the energy of the incident photons is less than the work function, no photoelectrons will be ejected. Lowering the work function of the material can increase the number of photoelectrons ejected.

4. Surface area of the material: The number of photoelectrons ejected is also influenced by the surface area of the material exposed to the incident light. A larger surface area will result in more photoelectrons being ejected.

These factors collectively determine the number of photoelectrons ejected per second in photoemission.