A black rectangular surface of area 'A' emits energy 'E' per second at $27^\circ$C. If length and breadth is reduced to half of its initial value and temperature is raised to $327^\circ$C then energy emitted per second becomes

A monoatomic gas at pressure P having volume V expands isothermally to a volume 3V and then adiabatically to a volume 81 V. The final pressure of the gas is ($\gamma = 5/3$).

An ideal gas at $27^\circ$C is compressed adiabatically to $\left(\dfrac{8}{27}\right)$ of its original volume. If $\gamma = 5/3$, then the rise in temperature of a gas is

The translational kinetic energy of the molecules of a gas at absolute temperature (T) can be doubled by