Grade 10 physics
Current in Semiconductors, Liquids and Gases: Transistors, Electrolysis, Plasma
Electric current has different microscopic carriers in solids, electrolytes and ionized gases, producing distinct laws and technologies.
1. Core ideas and learning goals
- Semiconductor conductivity depends strongly on temperature, light and controlled donor or acceptor doping.
- A p-n junction conducts asymmetrically and forms the basis of diodes, while transistors use a small signal to control a larger current.
- In an electrolyte, positive and negative ions carry charge and electrode reactions transfer matter.
- Gas conduction requires ionization; electrons and ions can produce avalanches, glow discharge, arcs or sparks.
- Plasma is a quasineutral ionized gas with collective electromagnetic behaviour, not simply an ordinary hot gas.
2. Physical model
Electric current has different microscopic carriers in solids, electrolytes and ionized gases, producing distinct laws and technologies.
Electric current has different microscopic carriers in solids, electrolytes and ionized gases, producing distinct laws and technologies. The model links observable changes with measurable physical quantities and conservation laws.
Before applying a relation, specify the reference frame, system boundary, initial state and approximations. The conclusion is valid only while those conditions are satisfied.