Question

A star has a surface temperature of 30,000 K. At what wavelength does the peak radiation occur? 100 nm

Answer 1

Use the displacement law, peak wavelength = 0.0029/T =0.0029/30000 = 97nm

Answer 2

Answer : Wavelength is 97 nm.

Explanation :

It is given that,

The surface temperature of a star, $T=30,000\ K$

We have to find the wavelength where the peak radiation occurs.

We can find the wavelength using Wein's displacement law i.e.

$\lambda=\dfrac{b}{T}$

b is the Wein's constant $b=2.88\times 10^{-3}m.K$

So, $\lambda=\dfrac{2.88\times 10^{-3}\ m.K}{30,000\ K}$

$\lambda=9.6\times 10^{-8}\ m$

or $\lambda=97\ nm$

Hence, the correct option is (b).