As the temperature of a conductor increases,its resistivity and conductivity change. The ratio of resistivity to conductivity

$A$ conducting wire of length $l$,area of cross-section $A$,and electric resistivity $\rho$ is connected between the terminals of a battery. $A$ potential difference $V$ is developed between its ends,causing an electric current. If the length of the wire of the same material is doubled and the area of cross-section is halved,the resultant current would be:

$A$ metal rod of length $10 \text{ cm}$ and a rectangular cross-section of $1 \text{ cm} \times 0.5 \text{ cm}$ is connected to a battery across opposite faces. The resistance will be

$A$ wire of resistance $R$ is stretched until its radius is halved. What will be the new resistance (in $, R$)?

The temperature coefficient of resistance for a wire is $0.00125\,^{\circ}C^{-1}$. At $300\,K$ its resistance is $1\,\Omega$. The temperature at which the resistance becomes $2\,\Omega$ is .......... $K$.

The temperature coefficient of resistance of a resistor wire is $0.00125\,^{\circ}C^{-1}$. At $300\,K$,its resistance is $1\,\Omega$. At what temperature in $K$ will its resistance be $2\,\Omega$?