Question

A copper wire has a diameter of 0.5 mm and resistivity of 1.6 into 10 to the power 8 ohm metre what will be the length of wire to make its resistance 10 Ohm

Answer 1

directly apply R=p(L/a)
here R=10
a=3.14*0.25*0.25*10^-6
p=1.6*10^8
find l..