In a Wheatstone's bridge, three resistances P,Q and R connected in the three arms and the fourth arm is formed by two resistances `S_1 and S_2` connected in parallel. The condition for the bridge to be balanced will be

Options

A. `(P)/(Q) = (R(S_1 + S_2))/(S_1 S_2)`
B. `(P)/(Q) = (R(S_1 + S_2))/(2 S_1 S_2)`
C. `(P)/(Q) = ( R)/(S_1 + S_2)`
D. `(P)/(Q) = (2 R)/(S_1 + S_2)`

Answer

A

Explanation

`(P)/(Q) = (R)/(S_1 S_2//(S_1 + S_2)) rArr (P)/(Q) = (R(S_1 + S_2))/(S_1 S_2)`.