How much energy in kilowatt-hour $(kWh)$ is consumed in operating ten $50\,W$ bulbs for $10$ hours per day in a month ($30$ days)?

Consider an electrical conductor connected across a potential difference $V$. Let $\Delta q$ be a small charge moving through it in time $\Delta t$. If $I$ is the electric current through it,
$I$. the kinetic energy of the charge increases by $I V \Delta t$.
$II$. the electric potential energy of the charge decreases by $I V \Delta t$.
$III$. the thermal energy of the conductor increases by $I V \Delta t$.
Choose the correct option.

An electric bulb is rated $60\,W$,$220\,V$. The resistance of its filament is ............. $\Omega$.

$A$ total charge $Q$ flows across a resistor $R$ during a time interval $T$ in such a way that the current vs. time graph for $0 \rightarrow T$ is like the loop of a sine curve in the range $0 \rightarrow \pi$. The total heat generated in the resistor is

$Kilowatt-hour$ $(kWh)$ is a unit of

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: