$A$ wire of resistance $4 \,\Omega$ is stretched to twice its original length. The resistance of the stretched wire would be ........... $\Omega$.

$A$ tapered bar of length $L$ and end diameters $D_1$ and $D_2$ is made of a material of electrical resistivity $\rho$. The electrical resistance of the bar is

When a piece of aluminium wire of finite length is drawn through a series of dies to reduce its diameter to half its original value,its resistance will become ........ times.

$A$ 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 $1.0\, mm$?

The resistance of a resistance wire is $5\,\Omega$ at $50\,^{\circ}\text{C}$ and $6\,\Omega$ at $100\,^{\circ}\text{C}$. The resistance at $0\,^{\circ}\text{C}$ will be ............. $\Omega$.

The cross-sections of wires made of the same material and having the same length are shown in the figure. What can be said about their resistances?