A black sphere has radius $R$ whose rate of radiation is E at temperature T . If radius is made half and temperature 4 T , the rate of radiation will be

Ordinary bodies P and Q radiate maximum energy with wavelength difference $3 \mu \mathrm{~m}$. The absolute temperature of body P is four times that of Q. The wavelength at which body Q radiates maximum energy is

The average force applied on the wall of a closed container depends as $\mathrm{T}^{\mathrm{x}}$ where T is the temperature of an ideal gas. The value of $x$ is

Which of the following graphs between pressure and volume correctly show isochoric process?