Question
Question: The temperature of the sun is \(5500K\)and it emits maximum intensity radiation in the yellow region...
The temperature of the sun is 5500Kand it emits maximum intensity radiation in the yellow region (5.5×10−7m). The maximum radiation from the furnace occurs at wavelength 11×10−7m. The temperature of the furnace is
A. 1125K
B. 2750K
C. 5500K
D. 11000K
Solution
In this question, we are given the maximum intensity wavelength of the sun and its temperature. We have found the temperature of the furnace whose wavelength is given. So, for such questions we can use the Wien displacement law. Whose expression is λmT=const where λm is the wavelength and T is the temperature.
Complete step by step answer:
According to the Wein displacement law, it states that the black body radiation curve for different temperatures will peak at different wavelengths that are inversely proportional to the temperature.
λm∝T1 where λm is the maximum wavelength and T is the temperature of the radiation.
Or λmT=b(const)
According to the question:
Temperature of the sun is T1 =5500Kand wavelength be given by λ1=5.5×10−7m
And the wavelength of the furnace can be given by λ2=11×10−7 and temperature of the furnace=?
Using the Wien displacement law,
λ1T1=λ2T2
Putting the values
5.5×10−7×5500=11×10−7×T2
∴T2=2750K
So, Temperature of the furnace is 2750K
Hence, the correct option is B.
Note: Wien’s Law, named after the German Physicist Wilhelm Wien, tells us that objects of different temperatures emit spectra that peak at different wavelengths. Hotter objects emit radiations of shorter wavelength and hence they appear blue. Similarly, cooler objects emit radiations of longer wavelength and hence they appear reddish.Wien displacement law has nothing as displacement as its name. The term maximum wavelength is used for the wavelength with maximum energy. The value of constant for Wien displacement law is b=2.89×10−3mK