If light of wavelength corresponding to maximum intensity emitted from a surface of hot body at temperature T1 is used to cause photoelectric emission from a metallic surface, then maximum kinetic energy of the emitted photo electron is 6eV, which is 3 times the work function of the metallic surface. If the light of wavelength of maximum intensity emitted from a surface of same body at temperature T2(T2=2T1) is used, the maximum kinetic energy of photoelectrons emitted is (in eV)