In the given circuit,the $5\, \Omega$ resistor dissipates $45\, J/s$ of heat due to the current flowing through it. The power dissipated per second in the $12\, \Omega$ resistor will be .............. $W$.

In the circuit shown,the current through $R_2$ is zero. If $R_4 = 2\,\Omega$ and $R_3 = 4\,\Omega$,the current through $R_3$ will be ................. $A$.

$A$ uniform metallic wire carries a current of $2\,A$ when a $3.4\,V$ battery is connected across it. The mass of the uniform metallic wire is $8.92 \times 10^{-3}\,kg$,its density is $8.92 \times 10^3\,kg/m^3$,and its resistivity is $1.7 \times 10^{-8}\,\Omega\cdot m$. The length of the wire is $l = \dots\dots\dots\dots\,m$.

One end each of a resistance $r$,a capacitor $C$,and a resistance $2r$ are connected together. The other ends are respectively connected to the positive terminals of batteries $P$,$Q$,and $R$ having emfs $E$,$E$,and $2E$. The negative terminals of the batteries are then connected together. In this circuit,with steady current,the potential drop across the capacitor is:

Two resistors of $100 \Omega$ each are connected in series with a $9 \text{ V}$ battery. $A$ voltmeter of $400 \Omega$ resistance is connected to measure the voltage drop across one of the resistors. The voltmeter reading is . . . . . . $V$.

In a copper voltameter,the mass deposited in $30\, \text{s}$ is $m\, \text{g}$. If the current-time graph is as shown in the figure,the Electrochemical Equivalent $(ECE)$ of copper is: