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:

$A$ wire of $20 \Omega$ is immersed in ice. If $10 \ A$ current is passed through this wire for $1 \ minute$,the ice completely melts. The mass of the ice is nearly $(L_{\text{ice}} = 79.7 \ cal \ g^{-1})$

The $emf$ of a thermocouple, with one junction kept at $0^{\circ}C$, is given by the equation $e = at + bt^2$. The Peltier coefficient is given by:

Consider the circuit given here. The potential difference $V_{BC}$ between the points $B$ and $C$ is (in $V$)

The variation of current $(I)$ and voltage $(V)$ is as shown in figure $A$. The variation of power $P$ with current $I$ is best shown by which of the following graphs?

$A$ 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 $n\,?$