The figure shows a network of four resistances and three batteries. The current through the branch $CF$ is ............... $A$.

In the network shown,the cell of emf $E$ has internal resistance $r$ and the galvanometer shows zero deflection. If the cell is replaced by a new cell of emf $2E$ and internal resistance $3r$,keeping everything else identical,then:

Current measured by the ammeter $(A)$ in the given circuit when no current flows through the $10\,\Omega$ resistance is . . . . . . $A$.

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

If the charge on the capacitor is $1 \text{ mC}$ in the given circuit,then $\frac{R_1 R_2}{R_3} = \ldots \ldots \ldots \Omega$.

$A$ non-zero current passes through the galvanometer $G$ shown in the circuit when the key $K$ is closed and its value does not change when the key is opened. Then,which of the following statement$(s)$ is/are true?