Two wires of the same material have lengths $L$ and $2L$ and cross-sectional areas $4A$ and $A$ respectively. The ratio of their specific resistance would be

$A$ wire has a resistance of $3.1 \Omega$ at $30^{\circ} C$ and $4.5 \Omega$ at $100^{\circ} C$. The temperature coefficient of resistance of the wire is

In an experiment,the resistance of a material is plotted as a function of temperature. As shown in the figure,the plot of $\ln R(T)$ versus $1/T^2$ is a straight line. One may conclude that:

$A$ block has dimensions $1 \ cm, 2 \ cm$ and $3 \ cm$. The ratio of the maximum resistance to the minimum resistance between any pair of opposite faces of the block is:

The reciprocal of resistance is

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