Physics - Electricity and Magnatism

• How do objects become electrically charged?

  Friction, rubbing, or transfer of electrons between objects.
• What are the three main types of electric charges?

  - Positive charge: excess protons - Negative charge: excess electrons - Neutral: no net charge
• What is electrostatic force?

  A force that acts between two charged objects, resulting from the interaction of their electric fields.
• What affects electrostatic forces?

  - Distance between objects - Magnitude of charges - Orientation of charges (in case of parallel plates)
• What is the direction of electric field lines around a simple point charge?

  Away from the positive charge and toward the negative charge.
• How do parallel electric field lines from multiple point charges interact?

  Superpose; add the electric field at each point in space.
• What is the electric field direction around a dipole?

  Outward from the positive plate and inward to the negative plate.
• What happens when two point charges are placed close together?

  A dipole forms; a region with a net electric field.
• What is the electric field direction between two parallel charged plates?

  Away from the positive plate and toward the negative plate.
• What is the force on a charge q in an electric field E?

  F = qE
• What is the electric field due to a point charge at a distance r?

  E = (k * q) / r^2
• What is the force between two charges q1 and q2 at a distance r?

  F = k * q1 * q2 / r^2
• What is the relation between electric potential, potential energy, and charge?

  V = U/q
• What is the change in potential energy when a charge moves from one point to another in an electric field?


  ΔU = qΔV
• What is the work done when a charge moves from one point to another in an electric field?

  W = qΔV
• What are equipotential lines or surfaces?

  Lines or surfaces where the electric potential is constant.