Question

A particular star (assuming it as a black body) has a surface temperature of about $ 5\times {{10}^{4}}K $ The wavelength in nanometre at which its radiation becomes maximum is: (b = 0.0029 mK)

• A. 48
• B. 58
• C. 60
• D. 70

Answer 1

Answer: (B)

Given: Surface temperature $ (b=0.0029\,mK)T=5\times {{10}^{4}}K $ Applying, Weins displacement law $ {{\lambda } {m}}T=b=cons\tan t $ $ {{\lambda }_{m}}\times 5\times {{10}^{4}}=0.0029 $ $ {{\lambda }_{m}}=\frac{0.0029}{5\times {{10}^{4}}}=58\times {{10}^{-9}}m $ $ =58\,nm $