What is the ratio of energy emitted by a black body at temperatures $27^{\circ}C$ and $927^{\circ}C$?

The total energy radiated from a black body source is collected for one minute and is used to heat a quantity of water. The temperature of water is found to increase from $20^{\circ}C$ to $20.5^{\circ}C$. If the absolute temperature of the black body is doubled and the experiment is repeated with the same quantity of water at $20^{\circ}C$,the temperature of water will be....... $^{\circ}C$

The distance between the Sun and the Earth is $2 \times 10^{8} \ km$, the temperature of the Sun is $6000 \ K$, and the radius of the Sun is $7 \times 10^{5} \ km$. If the emissivity of the Earth is $0.6$, find the temperature of the Earth in thermal equilibrium (in $K$).

$A$ black body is heated from $27^oC$ to $127^oC$. The ratio of their energies of radiations emitted will be

$A$ star emits radiation with maximum intensity at a wavelength of $289.9 \, nm$. What is the intensity of the radiation emitted by the star? (Given: Stefan's constant $\sigma = 5.67 \times 10^{-8} \, W/m^2K^4$,Wien's constant $b = 2898 \, \mu m \cdot K$)

In the $MKS$ system,Stefan's constant is denoted by $\sigma$. In the $CGS$ system,the multiplying factor of $\sigma$ will be: