An electric heater rated $220 \,V$ and $550 \,W$ is connected to $AC$ mains. The current drawn by it is (in $\,A$)

One kilowatt hour is equal to

The emf of a battery is $2\, V$ and its internal resistance is $0.5 \,\Omega$. The maximum power which it can deliver to any external circuit will be ............. $watt$.

There are four bulbs of power $100 \,W, 200 \,W, 500 \,W$ and $1000 \,W$. Among these, which filament has the highest resistance? (Assuming the same voltage source)

If the current in an electric bulb is changed by $1\%$,then the percentage change in power will be ............. $\%$.

The resistance of a bulb filament changes with temperature. If a bulb rated at $220 \ V$ and $100 \ W$ is connected to a supply of $(220 \times 0.8) \ V$,the actual power consumed will be: