Fundamentals of electricity, definitions, units & effects of electric current
Fundamentals of electricity, definitions, units & effects of electric current Anandβ‘ Fundamentals of Electricity
Electricity is a form of energy that powers most of our tools, lights, machines, and appliances. As an electrician, itβs important to understand the basic concepts of electricity before handling electrical systems.
π Basic Definitions
πΉ Electricity
The flow of electric charge (electrons) in a conductor like a copper wire.
πΉ Electric Current (I)
The rate at which electric charge flows through a conductor.
π Formula:
Where:
= Current (in amperes)
= Charge (in coulombs)
= Time (in seconds)
πΉ Voltage (V)
Also called Potential Difference β it is the force that pushes electric current through a circuit.
π Measured in: Volts (V)
πΉ Resistance (R)
The opposition to the flow of electric current.
π Measured in: Ohms (Ξ©)
πΉ Conductor
A material that allows electricity to flow easily. Example: Copper, Aluminum.
πΉ Insulator
A material that does not allow electricity to pass. Example: Rubber, Plastic.
π’ Units of Basic Electrical Quantities
| π Quantity | π Unit Name | π€ Symbol |
|---|---|---|
| Electric Current | Ampere | A |
| Voltage | Volt | V |
| Resistance | Ohm | Ξ© |
| Power | Watt | W |
| Energy | Joule / kWh | J / kWh |
| Charge | Coulomb | C |
β‘ Effects of Electric Current
Electric current produces different types of effects when it flows through a conductor.
1. π‘ Heating Effect
Current produces heat when it flows through a resistance (like an electric iron or heater).
Example: Electric bulb, toaster.
2. 𧲠Magnetic Effect
Current creates a magnetic field around the conductor.
This effect is used in motors, relays, and transformers.
3. βοΈ Chemical Effect
Current can cause chemical reactions in a liquid.
Used in electroplating, battery charging.
4. π₯ Physiological Effect
When current passes through a human body, it can cause shock, burns, or even death.
Safety is very important in electrical work!
π Ohm's Law (Basic Concept)
Ohm's Law relates Voltage (V), Current (I), and Resistance (R):
If you know any two values, you can calculate the third.
It's the fundamental law for solving basic electrical circuits.
π§ Summary
β‘ Electricity is the flow of electrons.
π Basic units: Volt (V), Ampere (A), Ohm (Ξ©)
π₯ Current produces heat, magnetism, and chemical changes
β οΈ Always follow safety precautions when working with electricity.
π‘ Quote for Students:
βElectricity is invisible, but its effects are powerful β learn it, respect it, and work safely!β
Conductors and insulators
Conductors and insulators Anandβ‘ Conductors and Insulators
In electrical work, materials are classified based on how easily they allow electric current to pass through them.
π What is a Conductor?
A Conductor is a material that allows electricity to pass through it easily.
πΉ Properties of Conductors:
Have free electrons that move easily
Low resistance to electric current
Used to carry current in electrical circuits
π§ Common Conductors:
𧲠Copper β Best and most commonly used
π© Aluminum β Used in overhead cables
π₯ Gold & Silver β Excellent conductors but costly
π§ͺ Mercury β Liquid metal, used in some special switches
β What is an Insulator?
An Insulator is a material that does not allow electricity to pass through it easily.
πΉ Properties of Insulators:
High resistance to electric current
Electrons are tightly bound and do not move freely
Used to protect us from electric shock
𧡠Common Insulators:
π² Rubber β Used in gloves, wire coatings
πͺ΅ Wood β Used in tool handles
𧱠Plastic β Used in switches, plugs, sockets
π§ Glass, Porcelain β Used in insulators on electric poles
π Comparison Table: Conductors vs Insulators
| π Property | β‘ Conductors | π« Insulators |
|---|---|---|
| Electron Movement | Free movement of electrons | Electrons do not move freely |
| Resistance | Low | High |
| Allows Current | Yes | No |
| Uses | Wiring, terminals, contacts | Insulation, safety protection |
| Examples | Copper, Aluminum, Silver | Rubber, Plastic, Wood, Glass |
π§ Real-Life Examples
π Copper wires carry electricity inside walls.
𧀠Rubber gloves protect electricians from shock.
πͺ Glass insulators are used in high-voltage power lines.
π§° Plastic handles on screwdrivers prevent electric shock.
β οΈ Safety Note:
Always handle conductors carefully and ensure all live wires are properly insulated to prevent electric shocks and short circuits.
π§ Summary:
Conductors allow electric current to pass (e.g., Copper).
Insulators block electric current (e.g., Rubber).
Both are important for safe and efficient electrical systems.
Conducting materials and their comparison
Conducting materials and their comparison Anandβ‘ Conducting Materials and Their Comparison
Conducting materials are substances that allow electric current to pass through them easily. These are used in wires, cables, circuits, terminals, and other electrical components.
π Properties of Good Conducting Materials
A good conductor should have:
β Low resistance
β High conductivity
β Corrosion resistance
β Good mechanical strength
β Cost-effectiveness (if possible)
π Common Conducting Materials
1. 𧲠Copper (Cu)
Excellent conductor
Widely used in wiring and motor windings
Flexible and strong
2. π© Aluminum (Al)
Less conductive than copper but lighter and cheaper
Used in overhead transmission lines
3. π₯ Silver (Ag)
Best conductor of electricity
Very expensive
Used in specialized electronic equipment
4. πͺ Gold (Au)
Excellent conductor and does not tarnish
Used in high-end electronic contacts
5. π§ͺ Mercury (Hg)
Only liquid metal conductor
Used in thermometers and switches
6. πͺ΅ Graphite
A form of carbon, conducts electricity
Used in brushes of motors
π Comparison Table of Conducting Materials
| βοΈ Material | β‘ Conductivity | π² Cost | βοΈ Use Case | π Durability |
|---|---|---|---|---|
| Silver | π Very High | π°π°π° Very High | Special circuits, precision devices | Excellent |
| Copper | π High | π° Medium | House wiring, motors, electronics | Excellent |
| Aluminum | β Moderate | π° Low | Transmission lines, appliances | Good |
| Gold | π High | π°π°π° Very High | Connectors, microchips | Excellent |
| Mercury | β Low | π° Medium | Switches, measuring instruments | Low |
| Graphite | β Moderate | π° Low | Motor brushes, resistors | Moderate |
π§ Why Copper is Preferred in Wiring?
High conductivity
Easy to bend and solder
Corrosion-resistant
Long-lasting
π Note: Though silver is better, copper is used because it is affordable and efficient.
β οΈ Important Tips:
Never use poor-quality conductors; they may cause overheating and fire hazards.
Use aluminum only in proper size and fittings to avoid joint failures.
Always ensure conductors are properly insulated.
π§ Summary:
Conducting materials are chosen based on conductivity, cost, durability, and application.
Copper is the most widely used conductor.
Silver and gold are excellent but expensive.
Aluminum is good for large-scale transmission due to its light weight.