A black body at 200 K is found to exit maximum energy at a wavelength 14 μm. When its temperature is raised to 1000 K, then wavelength at which maximum energy emitted is

Question

A black body at 200 K is found to exit maximum energy at a wavelength 14 μm. When its temperature is raised to 1000 K, then wavelength at which maximum energy emitted is (A) 14 mm (B) 7 μ m (C) 2.8 μ m (D) 28 mm

Tardigrade Admin · Accepted Answer

By Wien's displacement law λm T = constant or λm1 T1=λm2 T2 = λm2=(λm1 T1/T2)=(14×200/1000)=2.8 μ m

Q. A black body at 200 K is found to exit maximum energy at a wavelength 14 $μ$ m. When its temperature is raised to 1000 K, then wavelength at which maximum energy emitted is

14 mm

$7 μ m$

$2.8 μ m$

28 mm

By Wien's displacement law
$λ_{m} T$ = constant
or $λ_{m 1} T_{1} = λ_{m 2} T_{2}$
= $λ_{m 2} = \frac{λ _{m 1} T _{1}}{T _{2}} = \frac{14 \times 200}{1000} = 2.8 μ m$

Q. A black body at 200 K is found to exit maximum energy at a wavelength 14 μm. When its temperature is raised to 1000 K, then wavelength at which maximum energy emitted is