A ring shaped tube contains two ideal gases with equal masses and molecular weight M1 = 32 and M2 = 28. The gases are separated by one fixed partition P and another movable conducting partition S which can move freely without friction inside the ring. The angle as shown in the figure α in equilibrium is:
(A) 7π / 8
(B) 14π / 16
(C) 15π / 16
(D) 16π / 15
