Question

A long copper wire of radius 0.321 mm has a linear charge density of 0.100 μC/m. Find the magnitude of the electric field near the surface of the wire. (in Mega Nm²/C, keep 2 significant figures) Mega=10⁶

Answer 1

Electric field due to a charged conductor wire, at the surface of wire is given by:

E = 2k/R

R = Radius of wire = 0.321 mm = 0.321*10^-3 m

= linear charge density = 0.100 C/m = 0.100*10^-6 C/m

k = 9*10^9

So, Using given values:

E = 2*9*10^9*0.100*10^-6/(0.321*10^-3)

E = 5.607*10^6 N/C

In two significant figures

E = 5.6 MN/C

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