Calculate radiation power for sphere whose temperature is 227$$^\circ$$C, radius 2 m and emissivity 0.8.

An ideal gas initially at pressure 1 bar is being compressed from $$30 \mathrm{~m}^3$$ to $$10 \mathrm{~m}^3$$ volume and its temperature decreases from $$320 \mathrm{~K}$$ to $$280 \mathrm{~K}$$, then find final pressure of the gas.

Assertion : Vibrational degree of freedom of a di-atomic gas molecule appears at every high temperature.

Reason : Di-atomic gas has two vibrational degree of freedom in one direction.

Assertion : $$\mathrm{NH}_3$$ is liquidities more easily than $$\mathrm{CO}_2$$.

Reason : Critical temperature of $$\mathrm{NH}_3$$ is more than $$\mathrm{CO}_2$$.