$A$ black body radiates maximum energy at wavelength $\lambda$ and its emissive power is $E$. Now,due to a change in the temperature of that body,it radiates maximum energy at wavelength $\frac{2\lambda}{3}$. At that new temperature,the emissive power is:

$A$ black body has a maximum wavelength $\lambda_{m}$ at a temperature of $2000 \ K$. Its maximum wavelength at $3000 \ K$ 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?

The temperature of a furnace is $200\,^{\circ}C$. In its spectrum,the maximum intensity is obtained at about $400\,\mathring{A}$. If the maximum intensity is at $200\,\mathring{A}$,calculate the temperature of the furnace in $^{\circ}C$. ......... $^{\circ}C$

$A$ hot source emits maximum radiation energy at a wavelength of $11 \times 10^{-5} \ cm$. According to Wien's displacement law,for what value of $n$ will a source at a temperature $n$ times the original temperature emit maximum energy at a wavelength of $5.5 \times 10^{-5} \ cm$?

The Earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by