Which of the following circuits follows Ohm's law?

In order to determine the $e.m.f.$ of a storage battery,it was connected in series with a standard cell in a certain circuit,and a current $I_1$ was obtained. When the battery is connected to the same circuit opposite to the standard cell,a current $I_2$ flows in the external circuit from the positive pole of the storage battery. What is the $e.m.f.$ $\varepsilon_1$ of the storage battery? The $e.m.f.$ of the standard cell is $\varepsilon_2$.

In steady state, a capacitor of capacitance $2 \mu F$ is charged to $4 \mu C$, as shown in the figure. If the internal resistance of the cell is $0.5 \Omega$, then the emf of the cell is (in $\text{V}$)

Ten $60 \, W, 220 \, V$ bulbs are connected in series to a $220 \, V$ supply. The power consumed in the circuit is ......... $W$.

For the circuit shown in the figure:
$(A)$ The current $I$ through the battery is $7.5 \text{ mA}$.
$(B)$ The potential difference across $R_L$ is $18 \text{ V}$.
$(C)$ The ratio of powers dissipated in $R_1$ and $R_2$ is $3$.
$(D)$ If $R_1$ and $R_2$ are interchanged,the magnitude of the power dissipated in $R_L$ will decrease by a factor of $9$.

$A$ cell of emf $E$ is connected to a resistance $R_{1}$ for time $t$ and the amount of heat generated in it is $H$. If the resistance $R_{1}$ is replaced by another resistance $R_{2}$ and is connected to the cell for the same time $t$, the amount of heat generated in $R_{2}$ is $4H$. Then the internal resistance $r$ of the cell is: