The length of a metallic wire is increased by $20 \%$ and its area of cross-section is reduced by $4 \%$. The percentage change in resistance of the metallic wire is $.......$ (in $\%$)

$A$ metal wire has a resistance of $35 \,\Omega$. If its length is increased to double by drawing it,then its new resistance will be (in $\Omega$)

$A$ nichrome wire $50 \text{ cm}$ long and $1 \text{ mm}^2$ cross-section carries a current of $4 \text{ A}$ when connected to a $2 \text{ V}$ battery. The resistivity of the nichrome wire in $\Omega \cdot \text{m}$ is:

At what temperature $(^{\circ} C)$ will the resistance of a copper wire become $3$ times its resistance at $0^{\circ} C$? (Given: Temperature coefficient of resistance $\alpha = 4 \times 10^{-3} {}^{\circ} C^{-1}$)

$n$ conducting wires of same dimensions but having resistivities $1, 2, 3, . . . , n$ are connected in series. The equivalent resistivity of the combination is

By increasing the temperature,the specific resistance of a conductor and a semiconductor respectively