Which of the following graphs represent the behavior of an ideal gas? Symbols have their usual meaning.

The correct relation between the degrees of freedom f and the ratio of specific heat $$\gamma$$ is :

Consider a mixture of gas molecule of types A, B and C having masses m_A < m_B < m_C. The ratio of their root mean square speeds at normal temperature and pressure is :

The amount of heat needed to raise the temperature of 4 moles of rigid diatomic gas from 0$$^\circ$$ C to 50$$^\circ$$ C when no work is done is ___________. (R is the universal gas constant).