What happens to the resistance of a conductor when its temperature is increased?

What is the minimum resistance which can be made using five resistors each of $1/5\,\Omega$?

$1 \text{ kWh} = 3.6 \times 10^6 \text{ joules}$. Is this statement true or false?

Derive the relation $R = R_{1} + R_{2} + R_{3}$ when three resistors $R_{1}, R_{2}$ and $R_{3}$ are connected in series in an electric circuit.

$A$ cylindrical conductor of length $l$ and uniform area of cross-section $A$ has resistance $R$. Another conductor of length $2l$ and resistance $R$ of the same material has area of cross-section:

How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistances in series connected to a battery?