For the circuit shown in the figure,the current $I$ will be .......$A$.

In the circuit shown below,the ammeter reading is zero. Then the value of the resistance $R$ is (in $Omega$)

In a Wheatstone bridge,three resistors $P$,$Q$,and $R$ are connected in three arms,and the fourth arm is formed by the parallel combination of two resistors $S_1$ and $S_2$. The condition for the bridge to be balanced is:

Kirchhoff's first law,$i.e.$,$\Sigma i = 0$ at a junction,is based on the law of conservation of:

In the circuit shown,the end $A$ is at potential $V_0$ and end $B$ is grounded. The electric current $I$ indicated in the circuit is

In the following circuit,the current $I_3$ is