Silicon and copper are cooled from $300 \ K$ to $100 \ K$. What happens to their specific resistance (resistivity)?

What is conductance? Write its unit.

$A$ rectangular parallelopiped is measured as $1\,cm \times 1\,cm \times 100\,cm$. If its specific resistance is $3 \times 10^{-7}\,\Omega\,m$,then the resistance between its two opposite rectangular faces (as shown in the figure) will be $.......... \times 10^{-7} \Omega$.

Specific resistance of a conductor increases with

The resistance of a wire at $0^{\circ} C$ is $20 \Omega$. If the temperature coefficient of resistance is $5 \times 10^{-3} {}^{\circ} C^{-1}$,the temperature at which the resistance will be double that at $0^{\circ} C$ is: (in $^{\circ} C$)

$n$ conducting wires of same dimensions but having resistivities $1, 2, 3, . . . , n$ are connected in series. The equivalent resistivity of the combination is