If the internal resistance of the battery is $1\, \Omega$, then what is the reading of the ammeter?

For the circuit shown,with $R_1 = 1.0\,\Omega$,$R_2 = 2.0\,\Omega$,$E_1 = 2\,V$ and $E_2 = E_3 = 4\,V$,the potential difference between the points $a$ and $b$ is approximately (in $V$):

The current in the arm $CD$ of the circuit will be

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

What is a Wheatstone bridge? Explain its principle.

Consider the following statements regarding the network shown in the figure.
$(1)$ The equivalent resistance of the network between points $A$ and $B$ is independent of the value of $G$.
$(2)$ The equivalent resistance of the network between points $A$ and $B$ is $\frac{4}{3} R$.
$(3)$ The current through $G$ is zero.
Which of the above statements is/are true?