Today I studied the Basic Electrical topic. I learned about AC and DC current, series and parallel wiring, and electrical symbols and colour coding. These are important basic concepts for understanding electrical systems.
1. Difference Between AC and DC Current
AC (Alternating Current) is an electric current that changes its direction periodically. The electricity supplied to homes and buildings is generally AC.
DC (Direct Current) flows in only one direction. Batteries and cells are common sources of DC power.
| AC Current | DC Current |
|---|---|
| Direction changes periodically | Flows in one direction |
| Commonly supplied through power grids | Commonly obtained from batteries |
| Used in homes and industries | Used in electronic devices and battery-powered equipment |
| Example: Household electricity supply | Example: Battery |
Simple Example
- AC: Electricity from a wall socket.
- DC: Electricity from a battery.
2. Wiring – Series and Parallel
There are two basic ways of connecting electrical loads: series wiring and parallel wiring.
Series Wiring
In a series circuit, electrical components are connected one after another in a single path.
If one component fails or the circuit is broken, the current stops flowing through the entire circuit.
Example: Old-style decorative light strings can use series connections.
Parallel Wiring
In a parallel circuit, components are connected in separate branches.
If one component fails, the other branches can continue to work. Household electrical wiring is generally arranged in parallel so that appliances can operate independently.
Difference Between Series and Parallel
| Series | Parallel |
|---|---|
| Single path for current | Multiple paths for current |
| Same current flows through components in the same series path | Current divides between branches |
| If one component opens, the whole path is interrupted | Other branches can continue working |
| Components are connected one after another | Components are connected across common supply points |
3. Electrical Symbols and Colour Coding
Electrical diagrams use standard symbols to represent components. Symbols make electrical circuits easier to understand and draw.
Some common electrical symbols include:
- Cell/Battery – represents a source of electrical energy.
- Switch – used to open or close a circuit.
- Lamp – represents a light.
- Resistor – limits the flow of current.
- Fuse – provides protection against excessive current.
- Earth/Ground – represents an earth connection.
- Motor – represents an electrical motor.
Electrical Wire Colour Coding
Wire colours help identify the purpose of conductors. In modern Indian installations, commonly used colours include:
- Brown – Live/Phase
- Blue – Neutral
- Green or Green/Yellow – Earth/Protective conductor
Colour conventions can vary by system and installation, so electrical work should always follow the applicable standards and site requirements.
Conclusion
Today I learned the basics of electrical systems. I understood the difference between AC and DC current, learned how series and parallel wiring works, and studied common electrical symbols and wire colours. These basic concepts will help me understand more advanced electrical topics in the future.
