Question

A black body has maximum energy at wavelength $ {{\lambda }_{m}} $ at temperature 2000 K. The corresponding wavelength at a temperature of 3000 K will be

• A. $ \frac{3}{2}{{\lambda }_{m}} $
• B. $ \frac{2}{3}{{\lambda }_{m}} $
• C. $ \frac{4}{9}{{\lambda }_{m}} $
• D. $ \frac{9}{4}{{\lambda }_{m}} $

Answer 1

Answer: (B)

From Wiens law
$ 2000\times {{\lambda }_{m}}=3000\times \lambda {{}_{m}} $
$ \lambda {{}_{m}}=\frac{2}{3}{{\lambda }_{m}} $