Answer:
Ω
Step-by-step explanation:
l=1000m
a=1mm2
p=1.68x10^-8
Electrical Resistivity Equation

where
p= proportional constant ρ (the Greek letter “rho”) is known as Resistivity.
L = is the length in metres (m)
A= is the area in square metres (m2),
R=1.68×10^-8×(1000/1×10^-6)
Ω