- Definition and Measurement
- Electric current is the flow of charged particles through conductors
- Current is measured in amperes (A) and represented by symbol I
- Current can be measured using ammeters or other devices
- Types and Conventions
- Conventional current flows in same direction as positive charges
- Current can be positive or negative, but conventionally flows in same direction
- Ohm's law states current is directly proportional to voltage and resistance
- Conductors and Materials
- Metals are highly conductive due to free electrons
- Electrolytes conduct current through ion movement
- Gases become conductors when electric field exceeds breakdown field
- Semiconductors have conductivity between conductors and insulators
- Physical Properties
- Current creates magnetic fields used in motors and transformers
- Current causes Joule heating in conductors
- Electromagnetic waves propagate at high speeds
- Superconductivity occurs below critical temperature with zero resistance