Question

as intensity of incident radiation with a threshhold frequency increases, ______ increases
a frequency of electrons ejected on the metal
b kinetic energy of photons
c frequency of photons
d threshhold work function of the metal

Explanation:

• Option A: Intensity of radiation (with frequency ≥ threshold) is related to the number of photons. More photons mean more electrons can be ejected (since each photon can eject one electron), so the frequency of ejected electrons (number per unit time) increases with intensity.
• Option B: Kinetic energy of ejected electrons (and photons' energy, but photon energy is \( E = h

u \)) depends on frequency (\(
u \)) of radiation, not intensity. So intensity doesn't affect photon kinetic energy (or electron KE beyond the threshold condition).

• Option C: Frequency of photons is determined by the source of radiation, not its intensity. Intensity is about the number of photons, not their frequency.
• Option D: Threshold work function (\( W_0 \)) is a property of the metal, independent of incident radiation intensity.

Answer:

A. frequency of electrons ejected on the metal