Q 12-03-023NEETNEET 2020Top questionMedium
A resistance wire connected in the left gap of a metre bridge balances a $10\ \Omega$ resistance in the right gap at a point which divides the bridge wire in the ratio $3 : 2$. If the length of the resistance wire is $1.5$ m, then the length of $1\ \Omega$ of the resistance wire is :
Answer: (B) $1.0 \times 10^{-1}$ m
Balance condition: $\dfrac{R}{10} = \dfrac{3}{2}$, so $R = 15\ \Omega$.
$15\ \Omega$ over $1.5$ m, so $1\ \Omega$ corresponds to
$$\frac{1.5}{15} = 0.1\ \text{m} = 1.0 \times 10^{-1}\ \text{m}$$
Solution by Sreeraj P, M.Sc Physics