The energy distribution $E$ with the wavelength $\lambda$ for black body radiation at temperature $T \ K$ is shown in the figure. As the temperature is increased,the maxima will:

The emissive power of a sphere of area $0.04 \,m^2$ is $0.7 \,kcal \,s^{-1} \,m^{-2}$. The amount of heat radiated in $20 \,s$ is: (in $\,kcal$)

Two stars emit maximum radiation of wavelength $3600 \ \mathring{A}$ and $4800 \ \mathring{A}$ respectively. The ratio of their temperatures is

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

The colour of a star is an indication of its

The maximum energy in the thermal radiation from a hot source occurs at a wavelength of $11 \times 10^{-5} \ cm$. According to Wien's law, the temperature of the source (on Kelvin scale) will be $n$ times the temperature of another source (on Kelvin scale) for which the wavelength at maximum energy is $5.5 \times 10^{-5} \ cm$. The value of $n$ is