Choose the answer that explains the photoelectric effect.

metallic plates emit protons only when light of a certain minimum frequency shines on them.
metallic plates emit electrons when the cumulative effect of light causes electron movement.
metallic plates emit electrons only when light of a certain maximum frequency accumulates energy.
metallic plates emit electrons only when light of a certain minimum frequency shines on them.

taylor's experiment:

accurately measured the speed of light
locked together the phases of two light sources so that the interference pattern would not shift
showed that man's reaction time was much slower than the speed of light
showed that individual photons have wave characteristics

1.

Metallic plates emit electrons only when light of a certain minimum frequency shines on them.

Explanation:

As we know by Einstein's equation of energy

here we know that

= work function of metal

KE = kinetic energy of ejected electrons

E = energy of incident light

So here electrons will eject only when light of sufficient minimum energy will incident on the metal plate.

2.

showed that individual photons have wave characteristics

Explanation:

Taylor did experiment with the source of light with very small intensity of light and then got the result of interference of light.

So here his experiment concluded that all light will show interference only due to one photon also.

So his experiment shows that one photon will give wave characteristics