Section 3.10: Unit 3 Test

This test covers all topics in Unit 3: Coulomb’s Law, electric fields, potentials, superposition, and point charges. Attempt all questions to evaluate your understanding.

Unit 3 Test Questions

  1. Two point charges +2 μC and -3 μC are 0.5 m apart. Calculate the magnitude and direction of the force on each charge.
  2. Three charges lie on a straight line: +1 μC, -2 μC, +3 μC, spaced 0.4 m apart. Find the net force on the middle charge.
  3. Determine the electric field at the midpoint between two charges +4 μC and +4 μC separated by 0.6 m.
  4. Four equal charges +1 μC are placed at the corners of a square of side 0.5 m. Find the net electric field at the center of the square.
  5. Calculate the electric potential at a point due to three point charges forming a triangle with sides 0.3 m, 0.4 m, and 0.5 m.
  6. Explain the difference between electric force and electric field, giving an example of each.
  7. Two charges +5 μC and -2 μC are separated by 0.3 m. Find the location along the line joining them where the electric field is zero.
  8. Compute the work done to bring a +1 μC test charge from infinity to the midpoint between two charges +3 μC and -3 μC separated by 0.6 m.
  9. Explain how the superposition principle is used to determine the net force or field in a system of multiple charges.
  10. Compare electric potential energy and electric potential for a system of three charges placed in a triangular configuration.