In determining the temperature of a distant star,one makes use of

The maximum wavelength of radiation emitted at $2000\;K$ is $4\;\mu m$. What will be the maximum wavelength of radiation emitted at $2400\;K$?

Two metal spheres have radii $r$ and $2r$ and they emit thermal radiation with maximum intensities at wavelengths $\lambda$ and $2\lambda$ respectively. The respective ratio of the radiant energy emitted by them per second will be .........

The temperature of a black body is $2880 \, K$. $U_1$ is the energy of radiation between $499 \, nm$ and $500 \, nm$,$U_2$ is the energy of radiation between $999 \, nm$ and $1000 \, nm$,and $U_3$ is the energy of radiation between $1499 \, nm$ and $1500 \, nm$. Given Wien's constant $b = 2.88 \times 10^6 \, nm \cdot K$,which of the following is correct?

On observing light from three different stars $P, Q$ and $R$, it was found that the intensity of violet colour is maximum in the spectrum of $P$, the intensity of green colour is maximum in the spectrum of $R$, and the intensity of red colour is maximum in the spectrum of $Q$. If $T_P, T_Q$ and $T_R$ are the respective absolute temperatures of $P, Q$ and $R$, then it can be concluded from the above observations that:

$A$ black body is at a temperature of $2880\;K$. The energy of radiation emitted by this object with wavelength between $499\;nm$ and $500\;nm$ is ${U_1}$,between $999\;nm$ and $1000\;nm$ is ${U_2}$ and between $1499\;nm$ and $1500\;nm$ is ${U_3}$. The Wien's constant $b = 2.88 \times {10^6}\;nm\,K$. Then