Answer:
The conductivity of the wire is
.
Step-by-step explanation:
Given that,
Diameter = 0.2 cm
Current = 20 A
Power = 4 W/m
We need to calculate the conductivity
We know that,

Using formula of resistance
....(I)
Where,
= resistivity
A = area
l = length
Using formula of power


Put the value of R in equation (I)



Put the all values into the formula


Hence, The conductivity of the wire is
.