Electric Field Lines Practice Problems

Two small charged spheres of charge q₁ = 30 μC and  q₂ = 45 μC are 10 cm apart as shown in the image.  Determine the net electric force exerted by the two spheres on a proton placed on the x-axis at i) x = 5 cm and ii) x = 15 cm.

Two tiny spheres of charge, q_A = -30 nC, and q_B = +60 nC, are placed at the corners A and B of a right triangle (OAB), as shown in the figure. Determine the magnitude and direction of the net electric field generated at O by these two spheres.

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 tiny particle of mass 5 × 10^-15 kg and a charge of 4 nC is accelerated from rest between two oppositely charged flat parallel sheets where there is a constant horizontal electric field of +280 N/C. The two sheets are separated by a distance of 5.0 mm. Find the speed of the particle 1 μs after being released.

Two infinite parallel sheets of opposite charge are separated by 25.0 cm. An electron is released from rest at the surface of the negative sheet and reaches the positive sheet 3 μs later. What is the magnitude of the electric field (E) between the two sheets?

A -16 nC tiny metallic sphere is placed at one corner of a square of side length 25 cm as shown in the image. Find the electric-field vector produced at the opposite corner of the square.

A metallic sphere of charge q and mass 1 kg is released from rest at a height d above a large plate. What magnitude and sign of charge would make the sphere suspended in the air? The electric field due to the plate is approximately 150 N/C and points toward the plate.