$A$ cable of resistance $10\,\Omega$ carries electric power from a generator producing $250\,kW$ at $10000\,V$. The power lost in the cable during transmission is ............. $kW$.

Which device can convert all electrical energy into heat?

$A$ $500\, W$ heating unit is designed to operate from a $115\, V$ line. If the line voltage drops to $110\, V$,the percentage drop in heat output will be ............... $\%$

Two conductors made of the same material are connected across a common potential difference. Conductor $A$ has twice the diameter and twice the length of conductor $B$. The power delivered to the two conductors $P_A$ and $P_B$ respectively is such that $P_A/P_B$ equals to

In a large building,there are $15$ bulbs of $40\ W$,$5$ bulbs of $100\ W$,$5$ fans of $80\ W$,and $1$ heater of $1\ kW$. The voltage of the electric mains is $220\ V$. The minimum capacity of the main fuse of the building will be ................ $A$.

You are given three bulbs of $25\, W$,$40\, W$,and $60\, W$. Which of them has the lowest resistance?