Question

There is an almost isotropic radiation coming to Earth from outer space from all direction, the so-called background radiation. This radiation corresponds to a temperature of 3 K. To which wavelength should we tune our antenna in order to detect this radiation?A. 966 mmB. 8.69 mmC. 8.69 μmD. 966 μm

Answer 1

D. 966 μm

Step-by-step explanation:

b = Wien's displacement constant =
`2.89* 10^(-3)\ mK`

T = Temperature

`\lambda_m` = Peak wavelength

Here the Wien's displacement law is used

`\lambda_m=(b)/(T)\\\Rightarrow \lambda_m=(2.89* 10^(-3))/(3)\\\Rightarrow \lambda_m=0.000963\\\Rightarrow \lambda_m=963* 10^(-6)\ m=963\ \mu m\approx 966\ \mu m`

The wavelength we should tune our antenna in order to detect this radiation is 966 μm