Understanding the basic concepts of electricity is very important for all competitive exams like SSC, RRB NTPC, UPSC, and State PSCs. One such fundamental concept is the difference between conductors and insulators.
This topic not only helps in science questions but also strengthens your understanding of day-to-day electrical appliances. So, let’s learn this topic in a very simple and easy-to-understand way! 💡
What is Electricity?
Electricity is the flow of electrons or electric charge through a material. Some materials allow electricity to pass through them easily, while some do not.
This gives us two important types of materials:
- Conductors
- Insulators
What is a Conductor?
A conductor is a material that allows electricity to pass through it easily.
Examples of Conductors
- Metals like copper, aluminum, gold, and silver
- Human body
- Saltwater
Why do conductors allow electricity?
Conductors have free electrons in them. These free electrons can move easily and carry the electric charge from one place to another.
Key Points
- Conductors are used to make wires and electrical circuits.
- They are also used in electrical switches, sockets, and plugs.
What is an Insulator?
An insulator is a material that does not allow electricity to pass through it easily.
Examples of Insulators
- Plastic
- Rubber
- Wood
- Glass
- Dry air
Why do insulators block electricity?
Insulators do not have free electrons. So, electric charge cannot move through them easily.
Key Points
- Insulators are used to cover wires so that we don’t get electric shocks.
- They are also used in the handles of tools, switchboards, and safety gloves.
Comparison Table: Conductor vs Insulator
| Feature | Conductor | Insulator |
|---|---|---|
| Definition | A material that allows electric current to pass through it easily. | A material that does not allow electric current to pass through it easily. |
| Electric Charge Flow | Free flow of electrons is possible. | Electrons are tightly bound, so no free flow of charge. |
| Presence of Free Electrons | Free electrons are present in large numbers. | Very few or no free electrons are present. |
| Electrical Conductivity | High conductivity (good conductor). | Very low or zero conductivity (poor conductor). |
| Resistance to Electricity | Offers low resistance to the flow of current. | Offers high resistance to the flow of current. |
| Thermal Conductivity | Also conducts heat well. | Poor conductor of heat. |
| Examples | Copper, Aluminum, Silver, Gold, Iron, Mercury | Rubber, Plastic, Wood, Glass, Dry Air, Paper |
| Uses | Used in wires, circuits, switches, connectors | Used for insulating wires, safety gloves, handles of tools |
| Behavior in Electric Field | Allows electrons to move freely in the field. | Does not allow movement of charge carriers. |
| Appearance in Electrical Devices | Found inside wires (core material). | Found outside wires (insulating cover). |
| Effect of Temperature | Conductivity decreases slightly with increase in temperature. | Resistivity may decrease slightly with temperature rise (in some cases). |
| Example in Real Life | Copper wire in your charger or fan. | Plastic covering of the same wire. |
| Safety Role | Must be handled with care to avoid shocks. | Provides protection against electric shocks. |
Real-Life Examples
Let’s look at some real-life uses of conductors and insulators:
Electrical Wires
- The inside of the wire is made of copper (a conductor).
- The outside is covered with plastic (an insulator).
Electrician’s Gloves
- Made from rubber to prevent electric shock.
Plug Points
- Metal pins (conductors) go inside the socket.
- Outer cover is made of plastic (insulator) for safety.
Tip for Competitive Exams
- Mnemonic to remember:
“Conductors Carry, Insulators Ignore” electricity. - Often asked in True/False, Match the Following, or One-liner MCQs in SSC, RRB, and UPSC exams.
Sample Questions
Which of the following is a conductor of electricity?
A) Rubber
B) Glass
C) Copper
D) Plastic
👉 Answer: C) Copper
What is the main use of insulators in electric wires?
A) To conduct electricity
B) To store electricity
C) To prevent electric shock
D) To make the wire shiny
👉 Answer: C) To prevent electric shock
Which of these is not a conductor?
A) Silver
B) Wood
C) Aluminum
D) Iron
👉 Answer: B) Wood
Final Summary
Let’s recap what we’ve learned:
- Conductors allow electricity to flow.
- Insulators block the flow of electricity.
- Metals are good conductors.
- Plastics, wood, and rubber are good insulators.
- Both are important for electrical safety and usage.
