Question

Three resistances $P,Q,R$ each of $2\Omega$ and an unknown resistance $S$ from the four arms of a Wheatstone bridge circuit. When a resistance of $6\Omega$ is connected in parallel to $S$ the bridge gets balanced. What is the value of $S$?

• A. $1\Omega$
• B. $2\Omega$
• C. $3\Omega$
• D. $6\Omega$

Answer 1

The correct option is C $3\Omega$

for balanced wheatstone bridge circuit
$\frac{2}{2}=\frac{2}{\left(\frac{6S}{S+6}\right)}\Rightarrow S+6=3S\Rightarrow S=3\Omega$