The kinetic energy of most energetic electrons emitted from a metallic surface is doubled when the wavelength `lamda` of the incident radiation is changed from 400 nm to 310 nm. The work function of the metal is

The K.E. of the most energetic electrons emitted from a metallic surface is doubled when the wavelength, lambda of the incident radiation is reduced from 400 nm to 310 nm. The work function of the metal is

The kinetic energy of the most energetic photoelectrons emitted from a metal surface is doubled when the wavelength of the incident radiation is reduced from lamda_1 " to " lamda_2 The work function of the metal is

The kinetic energy of the most energetic photoelectrons emitted from a metal surface is doubled when the wavelength of the incident radiation is reduced from lamda_1 " to " lamda_2 The work function of the metal is