Electric Circuit and it’s Components

Key Concepts

After this session, the student will be able to

• Symbols for various electrical components
• Source
• Conductor
• Switch

Introduction: 

A complete pathway that allows electrons to flow is called an electric circuit. The components included in an electric circuit are a battery, connecting wire, switch and any electric load. In this section, we are going to draw this electric circuit in our notebook by using symbols. 

Explanation: 

Electric circuit 

A complete pathway that allows electrons to flow is called an electric circuit. The components included in an electric circuit are a battery, connecting wire, switch and any electric load.  

All electric circuits are made of four basic components. They are: 

1. Source 

2. Conductor 

3. Load 

4. Switch 

The direction of the flow of electrons in an electric circuit is from the negative terminal towards the positive terminal of the battery. The electrons start from the negative terminal and move through the conducting wire.  Since the repulsion force is felt by the electrons in the front from the electrons at the back so the electrons in front are pushed such that they reach the positive terminal, and the circuit is complete. 

Source: 

Source is the source of electric energy in an electric circuit. It has a positive and a negative terminal. Current flows from the positive terminal of the battery towards the negative terminal of the battery, whereas the direction of the movement of electrons is opposite to the flow of the electron, that is, from the negative terminal of the battery towards the positive terminal of the battery. Examples of sources are cells and batteries. 

The symbol for a battery is made by joining two or more symbols for a cell together.  

Conductor: 

The wire through which electric current flows is called a conductor. It is made of a conducting material that allows the electric current to flow through it. There is no positive or negative terminal in a wire. 

The symbol for wire is:  

Switch: 

A device that can switch the circuit on or off by closing or opening the circuit is called a switch. There is no positive or negative terminal in a switch. 

Symbol used for switch is 

1. When the key of the switch is open, it makes the electric circuit open. 

2. When the key of the switch is closed, it makes the electric circuit close. 

Drawing a circuit diagram: 

Circuit symbols are used to represent the electrical components of a circuit. While drawing the circuit diagram the following steps should be done. 

1. Draw the circuit symbols first, then 

2. Draw all the connecting wires. 

3. Draw the diagram using a ruler.  

4. Make all the connecting wires and leads straight lines with corner angles as 90 degrees. 

5. Do not cross any of the conducting wires. 

Questions and answers 

Question 1: Draw an open electric circuit using bulb, battery and wire using the circuit symbol. 

Answer: 

Question 2: Draw a closed electric circuit using bulb, battery and wire using the circuit symbol. 

Answer:

Summary

1. Electric circuit has four basic components

• a. Source-cell, battery
• b. Load-bulb, heater, motor, geyser
• c. Conductor-wire
• d. Switch – can be off or on

2. The symbol for the electric circuit components are

• Cell
• Battery
• Wire
• Switch on
• Switch off

3. Electrons are pushed by each other resulting them in reaching the positive terminal.