$A$ heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

$A$ room heater is rated $400 \text{ W}$, $220 \text{ V}$. If the supply voltage drops to $200 \text{ V}$, what will be the power consumed (approximately) (in $\text{ W}$)?

Two heaters take $10$ minutes and $20$ minutes respectively to heat the same amount of water. If the heaters are connected in parallel,what would be the time required to heat the same amount of water?

Four wires of the same diameter are connected in turn between two points,maintained at a constant potential difference. Their resistivities and lengths are: $\rho$ and $L$ (wire $1$),$1.2\rho$ and $1.2L$ (wire $2$),$0.9\rho$ and $0.9L$ (wire $3$),and $\rho$ and $1.5L$ (wire $4$). Rank the wires according to the rates at which energy is dissipated as heat,greatest first.

One kilowatt hour is equal to

Electric power is transmitted over long distances through conducting wires at high voltage because