$A$ $12 \text{ HP}$ motor has to be operated $8 \text{ hours/day}$. How much will it cost at the rate of $50 \text{ paisa/kWh}$ in $10$ days? (in $Rs.$)

An electric bulb marked $40\, W$ and $200\, V$,is used in a circuit of supply voltage $100\, V$. Now its power is (in $, W$)

$A$ lamp is rated at $240 \ V, 60 \ W$. When in use,the resistance of the filament of the lamp is $20$ times that of the cold filament. The resistance of the lamp when not in use is: (in $Omega$)

$A$ current $i$ passes through a wire of length $l$, radius of cross-section $r$ and resistivity $\rho$. The rate of heat generation is

The current density in a circular wire is given by $J(r) = (1 \times 10^5 \text{ A/m}^3) r$,where $r$ is the radial distance and the wire's radius is $2 \text{ mm}$. If the potential applied across the wire is $70 \text{ V}$,then the energy consumed by the wire in $1000 \text{ s}$ is:

Explain electrical energy and power.