The current flowing through a lamp marked as $50\, W$ and $250\, V$ is ............. $amp$.

$A$ $10\, V$ storage battery of negligible internal resistance is connected across a $50\,\Omega$ resistor. How much heat energy is produced in the resistor in $1$ hour? (in $J$)

$A$ Watt-hour meter measures:

What is the value of $1 \, kWh$ in Joules?

An incandescent bulb has a thin filament of tungsten that is heated to high temperature by passing an electric current. The hot filament emits black-body radiation. The filament is observed to break up at random locations after a sufficiently long time of operation due to non-uniform evaporation of tungsten from the filament. If the bulb is powered at constant voltage, which of the following statement(s) is(are) true?
$(A)$ The temperature distribution over the filament is uniform
$(B)$ The resistance over small sections of the filament decreases with time
$(C)$ The filament emits more light at higher band of frequencies before it breaks up
$(D)$ The filament consumes less electrical power towards the end of the life of the bulb

$1\,\text{unit} =$ ...... electric energy.