If the ambient temperature is $300 \ K$,the rate of cooling at $600 \ K$ is $H$. In the same surroundings,the rate of cooling at $900 \ K$ is:

The energy spectrum of a black body exhibits a maximum of wavelength $\lambda_0$. The temperature of the black body is now changed such that the energy is maximum at wavelength $\frac{3\lambda_0}{2}$. The ratio of power radiated by the black body will be

If the temperature of the sun were to be increased from $T$ to $2T$ and its radius from $R$ to $2R$,then the ratio of the radiant energy received on the earth to what it was previously will be

$A$ black rectangular surface of area $A$ emits energy $E$ per second at $127^\circ C$. If length and breadth are reduced to half of their initial values and the temperature is raised to $527^\circ C$, then the energy emitted becomes:

Two spherical black bodies have radii $r_1$ and $r_2$. Their surface temperatures are $T_1$ and $T_2$. If they radiate the same power,then $\frac{r_2}{r_1}$ is:

Two black bodies $A$ and $B$ have equal surface areas and are maintained at temperatures $27^{\circ} C$ and $177^{\circ} C$ respectively. What will be the ratio of the thermal energy radiated per second by $A$ to that by $B$?