Question

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

97 nm
87 nm
0.01 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=(b)/(T)`

b is the Wein's constant
`b=2.88* 10^(-3)m.K`

So,
`\lambda=(2.88* 10^(-3)\ m.K)/(30,000\ K)`

`\lambda=9.6* 10^(-8)\ m`

or
`\lambda=97\ nm`

Hence, the correct option is (b).