⚡ Electromagnetism — Intermediate#

Scope — Quantitative laws governing electric and magnetic fields, circuits, and energy transfer.

Key concepts#

• Coulomb’s law — force between electric charges depends on charge magnitude and separation.
• Electric potential and voltage — energy per unit charge in an electric field.
• Circuits — closed paths allowing steady current flow.

Seed Q&A triads#

• Q: How does electric potential differ from electric field?
  A: Electric potential describes energy per charge; electric field describes force per charge.

• Q: Why is current the same everywhere in a series circuit?
  A: Charge conservation requires the same flow rate through all components in a single path.

• Q: How does resistance affect current?
  A: Higher resistance reduces current for a given voltage, as described by Ohm’s law.

Short exercises#

• Calculate current and power dissipation in a simple resistive circuit.
• Compare electric field strength near and far from a point charge.