In the following network potential at  $\mathrm{O}$  is 

In the following network, the current flowing through $15 \Omega$ resistance is

In the measurement of a resistance by the Wheatstone bridge, the known and the unknown resistance are interchanged to eliminate 

In a Wheatstone's metrebridge, the null point is obtained at the middle point of the wire. If in one gap the resistance is $10 \mathrm{\Omega }$, then the value of resistance in the other gap is 

The effective resistance between points $A$ and $\mathrm{B}$ is

In the Wheatstone's network given $P=10 \mathrm{\Omega }$, $Q=20 \mathrm{\Omega }$, $R=15 \mathrm{\Omega }$, $S=30 \mathrm{\Omega }$. The current passing through the battery (of negligible internal resistance) is

The potential difference between point $A$ and $\mathrm{B}$ in the following circuit is 

In a metrebridge, the balancing length from the left end (standard resistance of one $\mathrm{\Omega }$ is in the right gap) is found to be $20 \mathrm{cm}$. The value of the unknown resistance is 

In metre bridge experiment, with a standard resistance in the right gap and a resistance coil dipped in water (in a beaker) in the left gap, the balancing length obtained is $1$. If the temperature of water is increased, the new balancing