Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis? [figure]
- A and D
- B and D
- A only
- A and C
Answer
(3) A only
Solution
As per NCERT, for a frequency above the threshold frequency, the photoelectric current is directly proportional to the intensity of incident light (number of photons per second).
Current versus intensity is a straight line through the origin: graph A is correct.
Graph B shows a current that does not change with intensity: wrong.
As per NCERT, the saturation photoelectric current is independent of the frequency of incident radiation (for a given intensity and > 0).
Graphs C and D, in which the current rises linearly with frequency, are wrong (graph D is the shape of the stopping potential or maximum kinetic energy versus frequency graph).
Only A is correct.
Answer: (3)