An aluminium (resistivity $\rho = 2.2 \times 10^{-8} \Omega \cdot m$) wire of diameter $1.4 \text{ mm}$ is used to make a $4 \Omega$ resistor. The length of the wire is: (in $\text{ m}$)

Two wires $A$ and $B$ of the same material and same mass have radii $2r$ and $r$,respectively. If the resistance of wire $A$ is $34\,\Omega$,then the resistance of wire $B$ will be ............ $\Omega$.

$A$ wire of a certain material is stretched slowly by $10 \%$. Its new resistance and specific resistance become respectively:

$A$ copper wire is stretched to make it $0.5\%$ longer. The percentage change in its electric resistance if its volume remains unchanged is ................ $\%$

$A$ copper wire is stretched to increase its length by $0.1\%$. What is the percentage increase in the resistance of the wire (in $\%$)?

$A$ wire of length $1.0\, m$ and diameter $0.6\, cm$ has a resistance of $3.0 \times 10^{-3}\, \Omega$. What will be the resistance between the faces of a disc made of the same material with diameter $2.0\, cm$ and thickness $1.0\, mm$?