An electric kettle of $2 \mathrm{kW}$ is used for $2 \mathrm{h}$. Calculate the energy consumed in the units of kilowatt-hour and joule.

Write an expression for the amount of heat produced in a resistor when an electric current is passed through it, stating the meanings of symbols.

You are provided with a resistor, a key, an ammeter, a voltmeter, four cells of $1.5 \mathrm{V}$ each and few connecting wires. Using circuit components, draw a labelled circuit diagram to show the setup to study the Ohm's law. State the relationship between potential difference $\left(V\right)$ across the resistor and the current $\left(I\right)$ flowing through it. Also draw $V-I$ graph taking $V$ on the $X-\mathrm{axis}$.

Write the relationship between electrical resistance and electrical resistivity for a metallic conductor of cylindrical shape. Hence, derive the SI unit of electrical resistivity.

Find the resistivity of the material of a metallic conductor of length $2 \mathrm{m}$ and area of cross-section $1.4\times {10}^{-6} {\mathrm{m}}^2$. The resistance of the conductor is $0.04 \mathrm{ohm}$.

Two LED bulbs of $12 \mathrm{W}$ and $6 \mathrm{W}$are connected in series. If the current through $12 \mathrm{W}$ bulb is $0.06 \mathrm{A}$ the current through $6 \mathrm{W}$ bulb will be: