The figure below shows the plot of versus P for oxygen gas at two different temperatures.


Read the following statements concerning the above curves :
(i) The dotted line corresponds to the 'ideal gas' behaviour.
(ii) T₁ > T₂
(iii) The value of at the point where the curves meet on the y-axis is the same for all gases.
Which of the above statement is true ?

The average kinetic energy of a gas molecule at 27^o C is 6.21 x 10^-21 J. Its average kinetic energy at 227^o C will be

The coefficient of linear expansion of a crystal in one direction is  and that in every direction perpendicular to it is .  The coefficient of cubical expansion is :