Answer:
from the equation 1 below, the ratio of the resistivity of wire b to its resistance is twice the ratio of the resistivity if wire A to its resistance.
Explanation:
R=(ρL)/A
A =(ρL)/R
Where A is cross sectional area,
ρ is the resistivity
L is length of wire
R is resistance of wire.
from the question the two wires have same cross sectional area.
Aa =Ab ; hence
(ρaLa)/Ra = (ρbLb)/Rb
La =2Lb
(ρa*2Lb)/Ra = (ρbLb)/Rb
(2ρa)/Ra = (ρb)/Rb
ρb/Rb = 2* ρa/Ra ................... equ 1
