A photon has energy equal to `10^10 eV`. Calculate its wavelength.

The work function of a photosensitive material is 2.eV. Calculate its threshold wavelength.

The work function of a metal is 3eV. Calculate its threshold wavelength.

A photon with energy E is characterised by a wavelength given by

The frequency of the strong yellow line in the spectrum of sodium is 5.09xx10^14 sec^(-1) . Calculate the wavelength of this light.