Types of Electric Circuits: Series, Parallel, Open, Closed & Differences
An electric circuit is a defined path through which electric current moves. This pathway includes a device that supplies energy to the charged particles making up the current, such as a battery or generator. The circuit also includes devices that use the current, like lamps, electric motors, or computers, along with the connecting wires or lines that allow transmission.
Electric Circuit: Concept and Components
In any electric circuit, the flow of current is driven by an energy source. This source creates a potential difference, causing electrons to move through the pathway. The main components found in a typical electric circuit are:
- Power Source (battery or generator)
- Conducting Wires
- Electrical Devices (such as bulbs or motors)
For a current to flow, the circuit must form a closed loop. If the path is broken at any spot, the circuit is open, and current stops flowing. When the path is complete, it is called a closed circuit, and current travels from the source, through the devices, and back.
Types of Electric Circuits
Circuits can be arranged in different ways. The main circuit types are distinguished by how devices are connected and how current flows through them.
| Type | Description | Key Feature |
|---|---|---|
| Series Circuit | All devices are connected one after another along the path. | Same current passes through each device. |
| Parallel Circuit | Devices are connected across common points, making many branches. | Same voltage across each device; total current is split among branches. |
| Open Circuit | The path is broken at any point. | No current flows. |
| Closed Circuit | The path is complete from source to devices and back. | Allows current flow. |
How Electric Circuits Operate
When an electric circuit is closed, charged particles (usually electrons) are pushed by the energy source. The energy provided is then used by devices connected in the path, like lighting up a lamp or turning a motor. The connecting wires complete the circuit so current can return to the source.
Key Formulas in Electric Circuits
Understanding electric circuits also means knowing some essential relationships. Current, voltage, and resistance are related, and summarizing these in formulas aids in problem-solving.
| Formula | Explanation | Units |
|---|---|---|
| I = V / R | Current (I) in a circuit is the ratio of Voltage (V) to Resistance (R). | I: Ampere (A), V: Volt (V), R: Ohm (Ω) |
| V = IR | Voltage across a device is the product of current and resistance. | V: Volt (V) |
| P = VI | Electric power is the product of voltage and current. | P: Watt (W) |
Example: Simple Circuit Calculation
Suppose a lamp and a motor are connected in a simple circuit with a battery as the energy source. If the circuit forms a complete path, current flows from the battery, through the connecting wires, powering each device. If a switch in the circuit is open, the pathway is broken and current will not flow.
As a basic calculation, consider a circuit where a 12V battery is connected across a resistor of 6Ω:
- Find the current using I = V / R.
- The current flowing through the circuit is 2 amperes.
Step-by-Step Approach to Circuit Problems
- Identify all energy sources and devices in the circuit.
- Check if the circuit is open or closed.
- Note the arrangement: series or parallel.
- Apply the correct formula (I = V / R, V = IR, P = VI) as needed.
- Calculate stepwise, verifying each unit.
Common Devices in Electric Circuits
| Device | Role in Circuit | Learn More |
|---|---|---|
| Battery | Acts as a source of electrical energy. | Battery Connections |
| Resistor | Limits and controls the flow of current. | What is a Resistor? |
| Bulb (Lamp) | Uses current to produce light. | How Bulbs Work |
| Switch | Opens or closes the circuit path. | Circuit Switch |
Practice and Further Learning
Learning the basics of electric circuits is essential for understanding more advanced topics in electricity and electronics. As you encounter circuit-based questions, always start by identifying the circuit type and the function of each component.
For more examples and in-depth resources, explore related Vedantu topics or practice numericals through dedicated assignments.
FAQs on Electric Circuit – Meaning, Types, Symbols & Formulas
1. What is an electric circuit?
An electric circuit is a closed and continuous path through which electric current can flow. In a complete electric circuit, electricity travels from a power source, like a battery, passes through various components (such as bulbs, resistors, or switches), and returns to the source. If there is any break in the path, no current will flow.
2. What are the main components of an electric circuit?
The main components of an electric circuit include:
- Cell or Battery: Provides electrical energy.
- Conducting Wires: Connect elements and allow current to flow.
- Switch: Opens or closes the circuit to start or stop current flow.
- Bulb or Lamp: Converts electric energy to light.
- Resistor: Limits or controls current in the circuit.
- Ammeter and Voltmeter: Measure current and voltage respectively.
3. What are the types of electric circuits?
The main types of electric circuits are:
- Open Circuit: The path is broken; current does not flow.
- Closed Circuit: The path is complete; current flows.
- Series Circuit: Components are connected end-to-end; current is the same throughout.
- Parallel Circuit: Components are connected across common points; current splits across the branches and voltage remains the same.
4. How is an electric circuit diagram drawn?
An electric circuit diagram is drawn using standardized circuit symbols to represent components like cells, bulbs, switches, and wires. To draw:
1. Use straight lines for wires.
2. Use standard symbols for each component.
3. Label each part if required.
4. Indicate the direction of current from positive to negative terminal.
5. What is the difference between a series circuit and a parallel circuit?
Series Circuit: All components are arranged in a single path; the same current flows through all. Resistance adds up.
Parallel Circuit: Components are connected in branches; current splits across branches while voltage remains the same across each branch. Total resistance decreases as more branches are added.
6. What are the standard electric circuit symbols?
Standard electric circuit symbols include:
- A short and long line for a cell
- A set of alternating long/short lines for a battery
- A zigzag line for a resistor
- A circle with a cross for a bulb/lamp
- An open or closed line for a switch
- Lines for wires
- "V" inside a circle for voltmeter; "A" inside a circle for ammeter
These symbols are used in all NCERT and exam diagrams for clarity.
7. What is Ohm’s Law and its formula?
Ohm’s Law states that current (I) flowing through a conductor is directly proportional to the voltage (V) across it and inversely proportional to the resistance (R).
Formula: I = V/R
Where I = current (Ampere), V = voltage (Volt), R = resistance (Ohm).
8. What is the direction of current in an electric circuit?
The conventional direction of electric current is from the positive terminal of the power source, through the circuit components, and back to the negative terminal. In wires, electrons move from negative to positive, but current direction is always shown from positive to negative in diagrams and definitions.
9. What happens if the circuit is open?
An open circuit means there is a break or gap in the path, so no current can flow. Example: When a switch is off, the circuit is open and electrical devices, like bulbs, will not work.
10. How do you calculate the total resistance in series and parallel circuits?
In a series circuit:
Rtotal = R1 + R2 + R3 + ...
In a parallel circuit:
1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ...
This helps solve Board Exam and NEET/JEE numericals.
11. Why does a bulb light up in a closed circuit?
A bulb lights up because when the circuit is closed, an electric current flows from the power source through the bulb’s filament. The filament offers resistance, which causes it to heat up and produce visible light.
12. Can current ever get used up as it flows in a circuit?
No, current is not consumed as it flows in a circuit. The amount of current entering and leaving a component (like a bulb or resistor) is the same. Electrical energy may be used by components, but the current continues to flow along the complete path.
