If an electric current $I$ flows through a resistor $R$ in a circuit for time $t$,then the electrical energy $W$ consumed is given by:

Positive charges flow from high potential to low potential.

Draw a circuit diagram of an electric circuit containing a cell,a key,an ammeter,a resistor of $2\,\Omega$ in series with a combination of two resistors ($4\,\Omega$ each) in parallel and a voltmeter across the parallel combination. Will the potential difference across the $2\,\Omega$ resistor be the same as that across the parallel combination of $4\,\Omega$ resistors? Give reason.

Why is heat produced when a current is passed through a conductor?

$A$ piece of wire having resistance $R$ is cut into four equal parts. $(a)$ How will the resistance of each part compare with the original resistance? $(b)$ If the four parts are placed in parallel,how will the joint resistance compare with the resistance of the original wire?

State Joule's law of heating.