Two small spheres separated by a distance 2d lie on the x-axis. Each sphere carries a positive charge q. The origin of the x-axis lies at the midpoint of the two charges. What is the electric field magnitude and direction at the origin? Treat the spheres like point charges.

Four tiny spheres are charged to some charge value of "q". They are assembled to form a square with each side a length of "d". Half of the spheres are positively charged while the other half is negatively charged. Find the magnitude (in terms of q and d) and the direction of the electric field created by the four spheres at the center of the square. Assume that these tiny balls behave like point charges.

Two charges are assembled as shown. Calculate the electric field magnitude and direction at point p. Give direction as a CCW angle measured from an x-axis.

A 0.15 kg sparrow accumulates a +12 nC charge while perching on a power line. Determine the electric field (magnitude and direction) required for the sparrow to maintain its position in mid-air without flapping its wings.

Two tiny spheres of charge, q₁ = 2 μC and q₂ = 3 μC are separated by a distance of 31 cm and lie along the horizontal axis. The sphere with charge q₁ is on the left. Determine the electric field E vector at i) the midpoint between two charges and ii) 4 cm to the right of the charge q₂. 

A sodium ion, Na⁺, is placed in space where the electric field is E = (-500i + 200k) N/C. Determine the electric force on the sodium ion. Express the force in terms of its components.