$A$ battery consists of a variable number $n$ of identical cells (each having electromotive force $\varepsilon$ and internal resistance $r$) which are connected in series. The terminals of the battery are short-circuited and the current $I$ is measured. Which of the graphs shows the correct relationship between $I$ and $n\,?$

This question has Statement $1$ and Statement $2.$ Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement $1 :$ The possibility of an electric bulb fusing is higher at the time of switching $ON.$
Statement $2:$ Resistance of an electric bulb when it is not lit up is much smaller than when it is lit up.

When $1\,g$ of hydrogen $(e.c.e. = 1.044 \times 10^{-8}\,kg/C)$ forms water,$34\,kcal$ of heat is liberated. The minimum voltage required to decompose water is ............. $V$.

In a copper voltameter,the mass of copper deposited in $6 \, \text{min}$ is $m \, \text{g}$. If the current-time graph is as shown in the figure,the electrochemical equivalent of copper will be:

First,a set of $n$ equal resistors of $10 \; \Omega$ each are connected in series to a battery of emf $20 \; V$ and internal resistance $10 \; \Omega$. $A$ current $I$ is observed to flow. Then,the $n$ resistors are connected in parallel to the same battery. It is observed that the current is increased $20$ times. The value of $n$ is .... .

Two cells $A$ and $B$ of emf $2 \text{ V}$ and $1.5 \text{ V}$ respectively, are connected as shown in the figure through an external resistance $10 \text{ } \Omega$. The internal resistance of each cell is $5 \text{ } \Omega$. The potential difference $V_{A}$ and $V_{B}$ across the terminals of the cells $A$ and $B$ respectively are: