In a balanced meter bridge, the segment of wire opposite to a known resistance of \(70 \Omega\) is \(70…
In a balanced meter bridge, the segment of wire opposite to a known resistance of \(70 \Omega\) is \(70 \mathrm{~cm}\). The unknown resistance is
\(30 \Omega\)
\(60 \Omega\)
\(90 \Omega\)
\(15 \Omega\)
Solution
In balanced meter bridge known resistance,
\(S=70 \Omega, l=70 \mathrm{~cm}\)
\(\therefore\) Unknown resistance,
\(R=S\left(\frac{100-l}{l}\right)=\frac{70(100-70)}{70}=30 \Omega\)