[填空题]
1.An object X of surface r,/k e 3bzj:3ak,a r:c b)niwz/d cy*har,hw f+ec9ku k:ea $24.3\,cm^2$ emits 300W of radiation when its temperature is 1215K.
(1)State what is meant by emissivity.
(2)Show that this object is a blackbody radiator. e ≈
2.Calculate the peak wavelength of the emitted radiation. $λ_{max}$ = $\times10^{-6}\,m$
3.The object X is left to cool down until it reaches 800K. On the axes given, sketch the variation of intensity with wavelength of the radiation of object X at both the original 1215K and the cooler temperature of 800K. Label the graphs.
