(iv) The photoelectric emission is an instantaneous process without any
apparent time lag (~10– 9s or less), even when the incident radiation is
made exceedingly dim 11 5 PHOTOELECTRIC EFFECT AND WAVE THEORY
OF LIGHT
The wave nature of light was well established by the end of the nineteenth
century The phenomena of interference, diffraction and polarisation were
explained in a natural and satisfactory way by the wave picture of light