In a meter bridge a 30 resistance is connected in the left gap and a pair of resistances P and Q in the right gap. Measured from the left, the balance point is 37.5 ~cm , when P and Q are in series and 71.4 ~cm they are in parallel. The values of P and Q (in ) are

Step-by-step solution

Ist case aligned & 30 P+Q = l (100-l) & 30 P+Q = 37.5 (100-37.5) & 30 P+Q = 37.5 62.5 & P+Q= 30 62.5 37.5 aligned IInd case aligned 30 P Q P+Q & = l (100-l) 30(P+Q) P Q & = 71.4 (100-71.4) 30 50 P Q & = 71.4 28.6 P Q & = 30 50 28.6 71.4 aligned So, from Eqs. (i) and (ii), we get P=30 , Q=20