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

$A$ certain stellar body has radius $50 \,R_{s}$ and temperature $2 \,T_{s}$ and is at a distance of $2 \times 10^{10} \,AU$ from the earth. Here,$AU$ refers to the earth-sun distance and $R_{s}$ and $T_{s}$ refer to the sun's radius and temperature,respectively. Take both the star and the sun to be ideal black bodies. The ratio of the power received on earth from the stellar body as compared to that received from the sun is close to

$A$ black sphere of radius $R$ radiates power $P$ at a certain temperature $T$. If the temperature is doubled and the radius is also doubled,the new power radiated will be: (in $P$)

$A$ sphere,a cube,and a thin circular plate,all made of the same material,same mass,and same surface finish,are heated to a temperature of $200^{\circ} C$. Which of these objects will cool slowest when left in air at room temperature?

The energy spectrum of a black body exhibits a maximum around a wavelength $\lambda$. The temperature of a black body is now changed such that the energy is maximum at wavelength $2\lambda/3$. The power radiated by the black body will now increase by a factor of

The unit of Stefan's constant $\sigma$ is