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 ............ $\Omega$.

The reading of the ammeter in the following figure will be: (in $\text{A}$)

$A$ battery of $e.m.f.$ $3\, V$ and internal resistance $1.0\, \Omega$ is connected in series with a copper voltameter. The current flowing in the circuit is $1.5\, A$. The resistance of the voltameter will be ........... $\Omega$.

The figure shows a circuit having eight resistances of $1 \Omega$ each,labelled $R_1$ to $R_8$,and two ideal batteries with voltages $\varepsilon_1=12 V$ and $\varepsilon_2=6 V$. Which of the following statement$(s)$ is(are) correct?
$(A)$ The magnitude of current flowing through $R_1$ is $7.2 A$.
$(B)$ The magnitude of current flowing through $R_2$ is $1.2 A$.
$(C)$ The magnitude of current flowing through $R_3$ is $4.8 A$.
$(D)$ The magnitude of current flowing through $R_5$ is $2.4 A$.

$A$ voltmeter of resistance $150 \Omega$ connected across a cell of e.m.f. $3 \ V$ reads $2.5 \ V$. What is the internal resistance of the cell (in $\Omega$)?

When two identical resistors are connected in series to an ideal cell,the current through each resistor is $2 \ A$. If the resistors are connected in parallel to the same cell,the current through each resistor is: (in $A$)