The velocity of photoelectrons is `10^6 ms^-1` when light of wavelength `6000 A^@` falls on a metal surface. Calculate the work function of the metal.

The velocity of photoelectrons is 10^6 m//s when light of 4000A^@ falls on the metal surface. Calculate the work function of the metal.

Radiation of wavelength 5000 A^@ incidents on a metal surface to just cause photo emission. Calculate the work function of the metal.

Photoelectric emission occurs when light of wavelength 6000overset(@)(A) falls on a metal. Will this occur if light of wavelength 4500overset(@)(A) falls on the same metal? (Write Yes or No)