A black body at 200 K is found to emit maximum energy at a wavelength of `14mu m`. When its temperature is raised to 1000 K, the wavelength at which maximum energy is emitted is

Options

A. `14mum`.
B. `70mum`.
C. `2.8mum`
D. `2.4mum`.

Answer

C

Explanation

`lamda_mT=`constant
`implies((lamda_m)_2)/((lamda_m)_1)=(T_1)/(T_2)=(200)/(1000)=(1)/(5)`
`implies(lamda_m)_2=((lamda_m)_1)/(5)=(14xxmum)/(5)=2.8mum`