The resistance of a wire is $20 \Omega$. It is stretched,so that the length becomes three times,then the new resistance of the wire will be (in $\Omega$)

What is the resistance between the rectangular faces of a block with resistivity $3 \times 10^{-7} \, \Omega \cdot m$ and dimensions $1 \, cm \times 1 \, cm \times 100 \, cm$?

$A$ 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

The variations of resistivity $\rho$ with absolute temperature $T$ for three different materials $X, Y$ and $Z$ are shown in the graph below. Identify the materials $X, Y$ and $Z$.

If the length of a wire is doubled, its specific resistance (resistivity) will be.......

$A$ rod of a certain metal is $1.0 \, m$ long and $0.6 \, cm$ in diameter. Its resistance is $3.0 \times 10^{-3} \, \Omega$. Another disc made of the same metal is $2.0 \, cm$ in diameter and $1.0 \, mm$ thick. What is the resistance between the round faces of the disc?