Two wires of equal diameters,lengths $l_1, l_2$ and having resistivities $S_1, S_2$ respectively are joined in series. The equivalent resistivity of the combination is

Why does the resistance of metallic conductors and semiconductors change differently with a change in temperature?

$A$ wire of $1 \,\Omega$ has a length of $1\, m$. It is stretched until its length increases by $25\, \%$. The percentage change in resistance to the nearest integer is .....$\%$

There are two wires of the same length and of the same material and radii $r$ and $2r$. The ratio of their specific resistance is

The variation of applied potential and current flowing through a given wire is shown in the figure. The length of the wire is $31.4 \, cm$. The diameter of the wire is measured as $2.4 \, cm$. The resistivity of the given wire is measured as $x \times 10^{-3} \, \Omega \cdot cm$. The value of $x$ is . . . . . . [Take $\pi = 3.14$]

As the temperature increases,the electrical resistance: