When a resistance $R_1$ is connected across a cell,the current is $I_1$ and if the resistance $R_1$ is replaced by $R_2$,the current is $I_2$. Then the internal resistance of the cell is

For a cell, the graph between the potential difference $(V)$ across the terminals of the cell and the current $(I)$ drawn from the cell is shown in the figure. The $e.m.f.$ and the internal resistance of the cell are

For the circuit shown,the value of current at time $t=3.2 \, s$ will be ...... $A$. (Voltage distribution $V(t)$ is shown by Figure $1$ and the circuit is shown in Figure $2$)

$A$ heating coil is labelled $100\, W$,$220\, V$. The coil is cut in half and the two pieces are joined in parallel to the same source. The energy now liberated per second is .............. $J/s$.

If the power dissipated in the $3\,\Omega$ resistor is $27\,W$,then what is the power dissipated in the $2\,\Omega$ resistor (in $,W$)?

The resistance of an iron wire is $10\,\Omega$ and the temperature coefficient of resistivity is $5 \times 10^{-3}\,^{\circ}C^{-1}$. At $20\,^{\circ}C$,it carries $30\,mA$ of current. Keeping the potential difference between its ends constant,the temperature of the wire is raised to $120\,^{\circ}C$. The current in milliamperes that flows in the wire is: