Six equal resistances are connected between points P, Q and R as shown in the figure. Then the net resistance will be maximum between
P and Q
Q and R
P and R
any two points
Resistance between P and Q
RPQ = R || R3+R2 = R × 56RR = 56R= 511 R
Resistance between Q and R,
RRQ = R2 || R+R3 = R2 × 4R3R2 + 4R3= 411 R
Resistance between P and R,
RPR = R3 || R2+R = R3 × 3R2R3 + 3R2= 311 R
Hence it is clear that RPQ is maximum.