Question

Find the wavelength at which a black body radiates maximum energy, if its temperature is ${427}^o$C.(Wein's constant $b=2.898\times {10}^{-3}$ mK)

• A. $0.0414\times {10}^{-6}$m
• B. $4.14\times {10}^{-6}$m
• C. $41.4\times {10}^{-6}$m
• D. $414\times {10}^{-6}$m

Answer 1

The correct option is B $4.14\times {10}^{-6}$m

Temperature at which maximum energy is radiated $T={427}^{o}C$

$\therefore$ $T=427+273=700K$

From Wein's displacement law, wavelength ${\lambda }_{max}=\frac{b}{T}$

$\therefore$ ${\lambda }_{max}=\frac{(2.898\times {10}^{-3})}{700}$

$⟹$ ${\lambda }_{max}=4.14\times {10}^{-6}$ m