The reciprocal of resistance is

$A$ metal wire of $1 \text{ cm}$ length and $1 \text{ mm}$ radius has a resistance of $3 \times 10^{-3} \Omega$. If a wire of the same metal of length $3 \text{ cm}$ and radius $0.5 \text{ mm}$ is drawn,what is the resistance of the new wire (in $\Omega$)?

What is resistivity? Write its unit. On what factors does resistivity depend?

The masses of three wires of copper are in the ratio of $1 : 3 : 5$ and their lengths are in the ratio $5 : 3 : 1.$ The ratio of their electrical resistances is

Resistance of a wire is $8 \Omega$. It is drawn in such a way that it experiences a longitudinal strain of $400 \%$. The final resistance of the wire is (in $\Omega$)

Two solid conductors are made of the same material,have the same length,and have the same resistance. One of them has a circular cross-section of area $A_{1}$ and the other has a square cross-section of area $A_{2}$. The ratio $\frac{A_{1}}{A_{2}}$ is