Assuming that a given star radiates like a blackbody, estimate the wavelength of its strongest radiation when it emits a total intensity of 375 mwm? (b) find the temperature at its surface.

a) wavelength,

b) Surface temperature, T = 9017.89 K

Given:

Total Intensity, P = 375 MWm = 375

Here, total intensity is the power per unit area

Solution:

a) Using Wien's displacement law which gives the inverse relation between temperature and wavelength for black body radiation and is given by:

              (1)

where

k = proportionality constant = 2898

= maximum wavelength

T = Temperature in kelvin

From eqn (1):

          {2}

b) Temperature, T at the surface is given by Stefan-Boltzman law:

P =                                 (3)

where

Using eqn (3):

T = 9017.89 K

Now, substituting the value of T = 9017.89 K in eqn (2):

the correct choice is a .

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