Photoelectric Experiment: Intensity, Stopping Potential & Graphs
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 the light of the above statements, choose the most appropriate answer from the options given below:
Show answer and solution
Answer: (b)
- A: a sufficiently negative (retarding) potential stops even the fastest electrons, so the photocurrent becomes zero. A is true.
- R: , which is linear in . R is true.
- R only describes how varies with frequency; it does not explain why emission can be suppressed.
- So the answer is (b).