Two rods of equal length, one with a uniform positive
linear charge density of +1.5 × 10⁻⁹ C/m and the other with a
uniform negative linear charge density of -1.5 × 10⁻⁹ C/m,
are bent to form semicircles each of radius 0.3 m. These
semicircles are then joined to make a full circle. What is the
magnitude of the electric field at the center of the
circle?