Which device can convert all electrical energy into heat?

In the figure shown,the power generated in $y$ is maximum when $y = 5\,\Omega$. Then $R$ is

Power generated across a uniform wire connected across a supply is $H$. If the wire is cut into $n$ equal parts and all the parts are connected in parallel across the same supply,the total power generated in the wire is

Why is electric power transmitted at very high voltage over long distances to reduce Ohmic loss?

The number of electrons flowing per second in the filament of a $110 \,W$ bulb operating at $220 \,V$ is : (Given $e=1.6 \times 10^{-19} \,C$ )

$n$ identical bulbs,each designed to draw a power $P$ from a certain voltage supply,are joined in series across that supply. The total power which they will draw is