Consider one mole of a real gas A, with equation of state $P(V –b) =RT$ where ‘b’ is a constant. Which of the following is/are correct statement(s) about A? 
P = pressure, V=volume, T-temperature in Kelvin $R = 8.314J Kmo{l}^{-1}$ 

Potential energy of A, due to intermolecular forces, is either greater than (or) equal to that of ideal gas

Compressibility factor (Z) of A is directly proportional to ‘P’.

If 5J of heat is given to A and 2J work is done by the A then, its internal energy increases by 3J which is true for ideal gas also

Density of A is less than ideal gas $\forall$ P > 0