The length of a given cylindrical wire is increased by $100\,\%$. Due to the consequent decrease in diameter,the percentage change in the resistance of the wire will be ................ $\%$.

Resistivity of which of the following substances decreases on increasing the temperature?

The specific resistance of all metals is most affected by

The external diameter of a $5 \, m$ long hollow tube is $0.1 \, m$ and the thickness of its wall is $0.005 \, m$. If the resistivity $\rho = 1.7 \times 10^{-8} \, \Omega \cdot m$, then its resistance will be:

$A$ strip of copper and another of germanium are cooled from room temperature to $80\, K$. The resistance of

Two different conductors have the same resistance at $0\,^{\circ}C.$ It is found that the resistance of the first conductor at $t_1\,^{\circ}C$ is equal to the resistance of the second conductor at $t_2\,^{\circ}C.$ The ratio of the temperature coefficients of resistance of the conductors,$\frac{\alpha_1}{\alpha_2}$ is