In a Wheatstone's network, `P=2Omega, Q=2Omega, R=2Omega and S=3Omega`. The resistance with which S is to be shunted in order that the bridge may be balanced is

Options

A. `1Omega`
B. `2Omega`
C. `4Omega`
D. `6Omega`

Answer

D

Explanation

Let x be the resistance shunted with S for the bridge to be balanced.

For a balanced Wheatstone bridge.
`(P)/(Q)=(R)/(S.)or(2)/(2)=(2)/(S.)orS.=2Omega`
From figure, `(1)/(S.)=(1)/(S)+(1)/(x)or(1)/(2)=(1)/(3)+(1)/(x)`
or `(1)/(x)=(1)/(2)-(1)/(3)=(1)/(6)orx=6Omega`