Power of a lamp is $60\, W$. Find the energy in joules consumed by it in $1\, s$. (in $, J$)

Define electric power. Give its $SI$ units and write its mathematical equation.

An electric iron consumes energy at a rate of $840\, W$ when heating is at the maximum rate and $360\, W$ when the heating is at the minimum. The voltage is $220\, V$. What are the current and the resistance in each case?

The filament of an electric bulb is made of tungsten. Why?

The unit $Volt \times Ampere$ represents which physical quantity?

State Joule's law of heating.