The energy of a photon of wavelength λ is

The number of photoelectrons emitted

A metal emits no electrons if the incident light energy falls below certain threshold. For photo-emission, you would decrease

When light of wavelength 5000 Å falls on a metal surface whose photoelectric work function is 1.9 eV, the kinetic energy of the most energetic photoelectrons is

The threshold wavelengths for photoemission of two metals A and B are 300 nm and 600 nm, respectively. The ratio ${\mathrm{\Phi }}_A\mathrm{/}{\mathrm{\Phi }}_B\backslash Phi\_A/\backslash Phi\_B$ of their photoelectric work functions is

The photoelectric threshold wavelength of a certain metal is 3315 Å. Its work function is

The photoelectric work function of a certain metal is 2.5 eV. If the metal is separately irradiated with photons of energy 3 eV and 4.5 eV, the ratio of the respective stopping potentials is

Sodium and copper have photoelectric work functions 2.3 eV and 4.7 eV, respectively. The ratio ${\lambda }_{Na}\mathrm{/}{\lambda }_{Cu}\backslash lambda\_\{Na\}\; /\; \backslash lambda\_\{Cu\}$ 0f the threshold wavelengths for photoemission is about

Electrons are ejected from a metallic surface when light with a wavelength of 6250 Å is used. If light of wavelength 4500 Å is used instead,

UV radiation of energy 6.2 eV falls on molybdenum surface whose photoelectric work function is 4.2 eV. The kinetic energy of the fastest photoelectrons is