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: The photoelectric effect can be inhibited by applying a sufficiently negative potential to the material, increasing the energy required for electron emission beyond that supplied by incident radiation.
- Reason (R) is also correct: A negative electric potential halts electron emission by requiring more energy to overcome electron binding energy than is provided by the incident radiation's frequency. Therefore, (R) is correct but offers an incomplete explanation for (A). The correct option is (1).