Question

In given meter bridge circuit length of wire $AB$ is $1\, m .$ When resistance $X$ is shunted by $R$ resistance then balancing length from $A$ is found to be $20\, cm$. Find value of $R$ :-

• A. $\frac{6}{7} \Omega$
• B. $\frac{7}{6} \Omega$
• C. $\frac{1}{3} \Omega$
• D. $\frac{2}{3} \Omega$

Answer 1

Answer: (A)

$\frac{\frac{6 R}{6+R}}{3}=\frac{20}{80}=\frac{1}{4}$
$\frac{6 R}{6+R}=\frac{3}{4}$
$\Rightarrow R=\frac{6}{7} \Omega$