The figure shows a network of five resistances and two batteries. Which of the batteries is getting charged?

Find the equivalent resistance between points $A$ and $B$ for the given circuit.

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

Four resistors $A, B, C$ and $D$ form a Wheatstone bridge. The bridge is balanced when $C = 100 \ \Omega$. If $A$ and $B$ are interchanged,the bridge balances for $C = 121 \ \Omega$. The value of $D$ is: (in $\Omega$)

As shown in the figure,a $5\,V$ battery with $2\,\Omega$ internal resistance and a $2\,V$ battery with $1\,\Omega$ internal resistance are connected to a $10\,\Omega$ resistor. The current flowing through the $10\,\Omega$ resistor is:

What is the equivalent resistance between $A$ and $D$ in the given circuit? (All resistors are $10 \,\Omega$)