The re<span>sistance of the second wire is 16 R.
where R is the resistance of the first wire.
R = </span>ρ

where l = length of the wire
A = area of the wire
A =

where, r =

Thus, on finding the ratio of resistance of the two wires, we get,

here, R1 = R
l1 = 8m
l2 = 2m
A1=π

A1=π

we get. R2 = 16R
Answer:17.44A
Explanation: Current density=I/Area
Area is given by 2.79mm^2=2.79×10^-6m^2
Current=I=current density ×Area=6.25×10^6 ×2.79×10^-6=17.44A
IT WOULD act like an electromagnet even now
this same thing happens when we make use of solenoids. we have a wire wound around a hollow pipe , and that pipe would have air in it . as there is no natural vaccum here, the air will get ionised.. spreading charges .. around itself..