Three copper wires of lengths and cross-sectional areas are $(l, A)$,$(2l, A/2)$,and $(l/2, 2A)$. Resistance is minimum in

For wiring in the home,one uses $Cu$ wires or $Al$ wires. What considerations are involved in this?

Two wires are made of two different materials whose specific resistances are in the ratio $2:3$,lengths are in the ratio $3:4$,and cross-sectional areas are in the ratio $4:5$. The ratio of their resistances is:

Two conductors are made of the same material and have the same length. Conductor $A$ is a solid wire of diameter $1 \ mm$. Conductor $B$ is a hollow tube of outer diameter $2 \ mm$ and inner diameter $1 \ mm$. Find the ratio of resistance $R_A$ to $R_B$.

The resistance of an incandescent lamp is

Two wires of the same material are given. The first wire is twice as long as the second and has twice the diameter of the second. The resistance of the first will be