10. A length L of wire has a charge density of  C/m. What is the electric field at an axial distance r from the wire if L is 5 meters,  is 5 x 10-8 C/m and r is 10 cm. Use Gauss’s Law to solve.

Question

10.	 A length L of wire has a charge density of  C/m.  What is the electric field at an axial distance r from the wire if L is 5 meters,  is 5 x 10-8 C/m and r is 10 cm.  Use Gauss’s Law to solve.

Damon · Answer

I suspect a typo here. Yes, use Gauss's law if the length is great compared to the distance r here L = 5 and r = 0.1 Area of cylinder around wire at distance r is 2 pi r L integral of E coming out of surface = charge inside /eo so 2 pi r L E = 5*10^-8 L /eo so E = 5*10^-8 /(2 pi eo) = 10*10^-8 /(4 pi eo) = 10^-7 k