Six equal resistances are connected between points P, Q and R as shown in the figure. Then the net resistance will be maximum between

Resistance between P and QRPQ  = R ||  R3+R2  =  R ×  56RR =  56R=  511  RResistance between Q and R,RRQ  = R2 ||  R+R3  =  R2 ×  4R3R2 +  4R3=  411  RResistance between P and R,RPR  = R3 ||  R2+R  =  R3 ×  3R2R3 +  3R2=  311  RHence it is clear that RPQ is maximum.