Lamps used for household lighting are connected in

Different combinations of $3$ resistors of equal resistance $R$ are shown in the figures. The increasing order for power dissipation is:

The brightness of a bulb will be reduced,if a resistance is connected in

By using only two resistance coils—singly,in series,or in parallel—one should be able to obtain resistances of $3$,$4$,$12$,and $16\,\Omega$. The separate resistances of the coils are:

$A$ heater $A$ gives out $300 \ W$ of heat when connected to a $200 \ V$ $d.c.$ supply. $A$ second heater $B$ gives out $600 \ W$ when connected to a $200 \ V$ $d.c.$ supply. If a series combination of the two heaters is connected to a $200 \ V$ $d.c.$ supply,the heat output will be ................. $W$.

The current $I$ in the network shown in the figure is .......... $A$.