Q 11-11-011NEETJEE MainEAMCET 2014 (Engineering)Medium
Five moles of hydrogen initially at STP are compressed adiabatically so that its temperature becomes $673$ K. The increase in internal energy of the gas, in kilojoule, is ($R = 8.3$ J/mol K; $\gamma = 1.4$ for diatomic gas)
Answer: (C) $41.5$
$$\Delta U = nC_V\Delta T = n\frac{R}{\gamma - 1}\Delta T = 5 \times \frac{8.3}{0.4} \times (673 - 273) = 41500\ \text{J} = 41.5\ \text{kJ}$$
Solution by Sreeraj P, M.Sc Physics