Explanation:
The resistance of a wire is given by :
[tex]R=\rho\dfrac{l}{A}[/tex]
Where
[tex]\rho[/tex] is the resistivity of the wire
l = initial length of the wire
A = initial area of cross section
If length and the area of cross section of the wire is doubled then new length is l' and A', l' = 2 l and A' = 2 A
So, new resistance of the wire is given by :
[tex]R'=\rho\dfrac{l'}{A'}[/tex]
[tex]R'=\rho\dfrac{l}{A}[/tex]
R' = R
So, the resistance of the wire remains the same on doubling the length and the area of wire.
