QJEEM24Phcc56: JEE Main 2024 Physics - Class 12 JEEM24Phcc56 Solution: Given below are two statements: one is labelled as Assertion…
Given below are two statements: one is labelled as Assertion and the other is labelled as Reason R.
Assertion A: Number of photons increases with increase in frequency of light.
Reason R: Maximum kinetic energy of emitted electrons increases with the frequency of incident radiation.
In the light of the above statements, choose the most appropriate answer from the options given below:
Multiple Choice Options
- A is not correct but is correct.
- B is correct but is not correct.
- C Both and are correct and is the correct explanation of .
- D Both and are correct and is NOT the correct explanation of .
Step-by-Step Verified Solution
In order to determine the most appropriate answer to the question, let's analyze the given Assertion A and Reason R in detail.
Assertion A: Number of photons increases with increase in frequency of light.
This statement is not correct. The number of photons is determined by the intensity (or power) of the light and is given by the formula:
where is the number of photons per second, is the power (intensity) of the light, is Planck's constant, and is the frequency of the light. As the frequency increases, the energy per photon increases, but it does not necessarily mean that the number of photons increases unless the power of the light also increases proportionally.
Reason R: Maximum kinetic energy of emitted electrons increases with the frequency of incident radiation.
This statement is correct. According to the photoelectric effect, the maximum kinetic energy of emitted electrons is given by:
where is the maximum kinetic energy of the emitted electrons, is Planck's constant, is the frequency of the incident radiation, and is the work function of the material. As the frequency of the incident light increases, the kinetic energy of the emitted electrons increases.
Now, let's match the statements with the options given:
Option A: is not correct but is correct.
This option is correct because Assertion A is incorrect while Reason R is correct.
Option B: is correct but is not correct.
This option is incorrect because Assertion A is not correct.
Option C: Both and are correct and is the correct explanation of .
This option is incorrect because Assertion A is not correct.
Option D: Both and are correct and is NOT the correct explanation of .
This option is incorrect because Assertion A is not correct.
Therefore, the most appropriate answer is:
Option A: is not correct but is correct.