10. Two gases of equal mass are in thermal equilibrium.

If P_a,P_b and V_a and V_b are their respective pressures and volumes, then which relation is true

(a) P_a ≠P_b  ;  V_a = V_b                             (b)  P_a =P_b  ;  V_a ≠ V_b

(c) (P_a /V_a )  = (  P_b / V_b )                         (d)  P_aV_a = P_bV_b

Answer-d

(8)