The conductivity of a superconductor is

When the temperature of a wire is increased from $303 \ K$ to $356 \ K$,the resistance of the wire increases by $10 \%$. The temperature coefficient of resistance of the material of the wire is:

For wiring in the home,one uses $Cu$ wires or $Al$ wires. What considerations are involved in this?

The graph showing the variation of resistance $(R)$ of a metal wire as a function of its diameter $(D)$,while keeping other parameters like length and temperature constant,is:

The resistivity of alloys is $\rho_{\text{alloy}}$ and the resistivity of constituent metals is $\rho_{\text{metal}}$. Then,usually:

In the following diagram,the lengths of wires $AB$ and $BC$ are equal,but the radius of wire $AB$ is double that of $BC$. The ratio of the potential gradient on wires $AB$ and $BC$ will be (wires are made of the same material):