In the photoelectric effect experiment, if the frequency of incident light is increased beyond the threshold frequency while keeping its intensity constant, which of the following observations is/are correct?
Correct: B
The maximum kinetic energy ($ K.E = h(f - f_0) $) increases with frequency, but photoelectric current depends on intensity, not frequency. Since intensity is constant, the number of photons (and hence photoelectrons) remains the same, so the current stays constant. The correct answer is B. Students must distinguish between factors affecting kinetic energy and current.