Question

Figure shows a balanced Wheatstone net. Now, it is disturbed by changing $P$ to $11\, \Omega$. Which of the following steps will not bring the bridge to balance again?

• A. increasing $R$ by $2 \,\Omega$
• B. increasing $S$ by $20\, \Omega$
• C. increasing $Q$ by $10 \,\Omega$
• D. making product $R Q=2200(\Omega)^{2}$

Answer 1

Answer: (B)

$P / Q=R / S$. If $P$ is increased, then either $R$ or $Q$ should be increased or $S$ should be decreased.