Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speeds of emitted electrons will be

Photoelectric emission occurs only when the incident light has more than a certain minimum

In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by

When monochromatic radiation of intensity $$I$$ falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T respectively. If the intensity of radiation is 2$$I$$, the number of emitted electrons and their maximum kinetic energy are respectively