In the following circuit,the terminal voltage across the cell is (in $V$)

$A$ battery of $e.m.f.$ $10 \, V$ and internal resistance $3 \, \Omega$ is connected to a resistor $R$ as shown in the figure. If the current in the circuit is $0.5 \, A$,then the resistance of the resistor $R$ will be ............. $\Omega$.

For ensuring the dissipation of the same energy in all three resistors $(R_1, R_2, R_3)$ connected as shown in the figure,their values must be related as:

In the circuit shown below,the current that flows from $a$ to $b$ when the switch $S$ is closed is ............... $A$.

By a cell,a current of $0.9\, A$ flows through a $2\, \Omega$ resistor and $0.3\, A$ flows through a $7\, \Omega$ resistor. The internal resistance of the cell is ............ $\Omega$.

Three resistors having resistances $r_{1}, r_{2}$ and $r_{3}$ are connected as shown in the given circuit. The ratio $\frac{i_{3}}{i_{1}}$ of currents in terms of resistances used in the circuit is :