Wien’s law is stated as follows: λmT = C, where C is 2898 μm.K and λm is the wavelength at which the emissive power of a black body is maximum for a given temperature T. The spectral hemispherical emissivity (ελ) of a surface is shown in the figure below (1 Å = 10-10 m). The temperature at which the total hemispherical emissivity will be highest is K (round off to the nearest integer).