Question

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). 
Assertion (A): Emission of electrons in photoelectric effect can be suppressed by applying a sufficiently negative electron potential to the photoemissive substance. 
Reason (R): A negative electric potential, which stops the emission of electrons from the surface of a photoemissive substance, varies linearly with frequency of incident radiation. 
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both (A) and (R) are true but (R) is not the correct explanation of (A)
• B. (A) is true but (R) is false
• C. Both (A) and (R) are true and (R) is the correct explanation of (A)
• D. (A) is false but (R) is true

Hint:

In photoelectric effect problems, remember that the emission of electrons depends on the energy of the incident photons (which is related to frequency), but the suppression of this emission depends on the applied electric potential.

Answer 1

The Correct Option is A

- Assertion (A) is correct because the photoelectric effect can indeed be suppressed by applying a sufficiently negative potential to the material, as the energy required to remove electrons becomes greater than the energy provided by the incident radiation. 
- Reason (R) is also correct, as a negative electric potential does indeed stop the emission of electrons, but it does not depend on the frequency of the incident radiation, but rather on the energy required to overcome the binding energy of the electrons. Thus, (R) is correct but does not explain (A) fully. The correct answer is option (1).