

Quiz 3  Uniform Line Charge
A uniform line charge 1 (parallel to x axis),
ρ_{L1}=2πε_{o}×10nC/m, crosses the yz plane at y=1 and z=0, while another
line charge 2 (again parallel to x axis), ρ_{L2}=2πε_{o}×20nC/m, crosses
the yz plane at y=0, z=2 (Figure below shows the geometry).
(a) Find the electric field E1 (magnitude and direction) at the origin due to line charge 1.
(b) Find the electric field E2 (magnitude and direction) at the origin due to line charge.
(c) Find the total electric field E = E1 + E2 at the origin.
(d) Find the magnitude and direction of the force F that this field will exert on a
negative charge Q=5nC placed at the origin. (Hint: Start with the expression for the
field due to a line charge in the cylindrical coordinates, and then plug in for various
quantities. Write unit vector ρ of cylindrical system in terms of unit vectors of
Cartesian system x, y, z, making it easier to add the fields).
Physics key words: EM, transmission line electricity and magnetism, physics quiz, solutions,
uniform line charge, wavelength, lambda, electric field, vector, magnitude.
