Question

A long, straight metal rod has a radius of 5.50 cm and a charge per unit length of34.0 nC/m. Find the electric field atthe following distances from the axis of the rod, where distancesare measured perpendicular to the rod.

(a) 3.50 cm
_______N/C, Direction_________

(b) 11.5 cm
_______N/C,Direction_________

(c) 135 cm
_______ N/C, Direction________

Answer 1

Answer: a) 0 N/C ; b)5.31*10^3 N/C radial direction ; c) 452.92 N/C radial direction

Explanation: In order to solve this problem , first of all we have to calculate the electric field for the large straight metal rod.

To do that we have to use the Gaussian law as follows:

∫E.ds=Q inside of teh gaussian surface/ε0

E*2*π*r*L=Qinside/ε0

E=λ/(2*π*ε0*r) the we replace the data to calculate the field in every point.

To radius value inside the metal rod we have to consider that the charge are located at the surface so in this case the electric flux is zero this E=0.