Consider the four circuits shown in the figure given below. In which circuit is the power dissipated the greatest? (Neglect the internal resistance of the power supply)

$A$ constant voltage of $50 \ V$ is maintained between the points $A$ and $B$ of the circuit shown in the figure. The current through the branch $CD$ of the circuit is (in $A$)

By a cell,a current of $0.9\, A$ flows through a $2\, \Omega$ resistor and $0.3\, A$ flows through a $7\, \Omega$ resistor. The internal resistance of the cell is ............ $\Omega$.

$A$ wire of cross-section area $A$,length $L_1$,resistivity $\rho_1$ and temperature coefficient of resistivity $\alpha_1$ is connected to a second wire of length $L_2$,resistivity $\rho_2$,temperature coefficient of resistivity $\alpha_2$ and the same area $A$,so that the wires carry the same current. The total resistance $R$ is independent of temperature for small temperature changes if (Thermal expansion effect is negligible):

Two wires of the same material are connected in parallel to a circuit. If the ratio of their lengths is $4/3$ and the ratio of their radii is $2/3$,then the ratio of the electric current flowing through the wires will be .......

The resistance of a hot tungsten filament is about $10$ times its cold resistance. What will be the resistance of a $100\, W$ and $200\, V$ lamp when not in use? (in $\Omega$)