An aluminum wire of diameter D and length L has a resistance of 1.5 Ω. Find the length of another aluminum wire at the same temperature if its diameter is 2D and its resistance is 6 Ω.
Wire of the first case , Aluminum has the following information .
Length = L
Resistance = 1.5
Diameter = D
= Resistivity is constant for all size of one type of material at a particular temperature .
Therefore the second aluminum also has the same resistivity as=
the second aluminum piece has the following information,
R= 6 Diameter = 2D ,
Length of the wire = =