Question

in a meter bridge$,$ the balance point is found to be $40cm$ from one end $($say end A$).$ if a resistance of $10\Omega$ is connected in series with $R,$ a balance point is obtained $60cm$ from end $A.$ What are the values of $R$ and $S$ $($S is other resistance in series with $R)?$

Answer 1

Initially resistance are $R$ and $S$ inn the left and right gap of meter bridge$.$

According to formula$,$ $\frac{R}{S}=\frac{1}{100-1}$

therefore $\frac{R}{S}=\frac{2}{3}$

$S=\frac{3R}{2}$

After connecting resistance $qo$ series with $R$

$R+\frac{10}{S}=\frac{3}{2}$

Substituting $S=\frac{3R}{2}$ we get

$\frac{2R+20}{3R}=\frac{3}{2}$

$5R=40$ thus $R=8.$

S=12.