Two equal resistances when connected in series to a battery, consume electric power of $60\,W.$ If these resistances are now connected in parallel combination to the same battery, the electric power consumed will be .............. $W$

Two bulbs of equal wattage, one having carbon filament and the other having a tungsten filament are connected in series to the mains, then

Two cities are $150\,\, km$ apart. Electric power is sent from one city to another city through copper wires. The fall of potential per $km$ is $8\,\, volt$ and the average resistance per km is $0.5 \,\,\Omega .$ The power loss in the wire is

Assertion : When current through a bulb decreases by $0.5\%$, the glow of bulb decreases by $1\%$.

Reason : Glow (Power) which is directly proportional to square of current.

$A$ wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by $\Delta T$ in time $t. N$ number of similar cells is now connected in series with a wire of the same material and cross section but of length $2L$. The temperature of the wire is raised by the same amount $\Delta T$ in the same time $t$. The value of $N$ is :

The total power dissipated in watt in the circuit shown here is ............. $W$