$A$ wire has a resistance of $6 \,\Omega$. It is cut into two equal parts and both parts are connected in parallel. The new resistance is ................ $\Omega$.

The resistance across $M$ and $N$ in the given figure is

Two bulbs are connected in parallel. Bulb $A$ is brighter than bulb $B$. If $R_A$ and $R_B$ are their resistances respectively,then:

$A$ 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 ................. $W$.

$A$ wire of resistance $R$ is bent to form a square $ABCD$ as shown in the figure. The effective resistance between $E$ and $C$ is ( $E$ is the mid-point of arm $CD$ ).

An electric kettle has two filaments. The first filament boils a certain amount of water in $10 \text{ minutes}$ and the second filament boils it in $15 \text{ minutes}$. If both filaments are connected in parallel,the water will boil in .............. minutes.