Physics 102: Electricity & Magnetism

Electric Charge

A fundamental property of matter that causes it to experience a force in an electromagnetic field. Exists as positive (protons) or negative (electrons), measured in coulombs (C).

Coulomb's Law

The force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them (F = kq1q2/r^2).

Electric Field

A region around a charged object where other charges experience a force. Field strength E = F/q, measured in newtons per coulomb (N/C).

Electric Current

The flow of electric charge through a conductor, measured in amperes (A), where 1 ampere equals 1 coulomb per second.

Voltage (Electric Potential Difference)

The difference in electric potential energy per unit charge between two points, measured in volts (V). It drives current through a circuit.

Resistance

A measure of the opposition to the flow of electric current in a material, measured in ohms. Depends on material, length, cross-section, and temperature.

Ohm's Law

The current through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance (V = IR).

Electric Circuit

A closed loop or pathway through which electric current can flow, consisting of a power source, conductors, and load components.

Series Circuit

A circuit in which components are connected end to end, providing a single path for current flow. Total resistance is the sum of individual resistances.

Parallel Circuit

A circuit in which components are connected across the same two points, providing multiple paths for current flow. Total resistance is less than the smallest individual resistance.