In a Wheatstone bridge, resistances P, Q, and R are 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=(2R)/(S_1+S_2)`
B. `P/Q=(R(S_1+S_2))/(S_1S_2)`
C. `P/Q=(R(S_1+S_2))/(2S_1S_2)`
D. `P/Q=R/(S_1S_2)`

Explanation

For balanced Wheatstone bridge.
`P/Q=R/S` Here `S=S_1||S_2=(S_1S_2)/(S_1+S_2) implies P/Q=(R(S_1+S_2))/(S_1S_2)`