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:

$A$ copper voltameter is connected in series with a heater coil of resistance $0.1\,\Omega$. $A$ steady current flows in the circuit for $20$ minutes and a mass of $0.99\,g$ of copper is deposited at the cathode. If the electrochemical equivalent of copper is $0.00033\,g/C$, then the heat generated in the coil is ............... $J$.

An ammeter and a voltmeter are connected in series with a cell. Their readings are $A$ and $V$ respectively. If a resistor is now connected in parallel with the voltmeter,then:

Which of the following graphs represents the variation of power loss $P$ in the external load with external resistance $R$?

$A$ thermocouple is made of $Cu$ and $Fe$. If a battery is connected in it,then

The value of the resistance $R$ in the figure is adjusted such that the power dissipated in the $2\,\Omega$ resistor is maximum. Then the power dissipated in the $2\,\Omega$ resistor will be ................ $W$.