Question

In an experiment of Wheatstone bridge, a null point is obtained at the centre of the bridge wire. When a resistance of $10 \, \Omega$ is connected in one gap, the value of resistance in other gap is

• A. $10\, \Omega$
• B. $5 \,\Omega$
• C. $\frac{1}{2}\,\Omega$
• D. $500\,\Omega$

Answer 1

Answer: (A)

$10\, \Omega$

Answer 2

According to Wheatstone bridge principle $\frac{P}{Q}=\frac{R}{S}$ Let length of bridge wire is $100\, cm$. $\therefore \frac{R}{S}=\frac{l}{100-l}$ Here $R=10 \,\Omega, l=50\, cm$ $\frac{10}{S} =\frac{50}{100-50}$ $S =10\, \Omega$