In this article, you’ll learn what is an electric circuit and it’s different types of circuits with diagrams.
Electric Circuits and Types
An electric circuit, also known as an electrical circuit, is a conductor used to move current or electricity.
To establish a connection between the source of voltage and the load, a conductive wire is used. The source and load are separated by a fuse and an ON/OFF switch.
Depending upon the type of current flowing, the electric circuit is classified into D.C. circuit and A.C. circuit.
Types of Electrical Circuits with Diagram
Following are the types of electrical circuits with diagram:
- D.C. Circuit
- A.C. Circuit
- Closed-circuit
- Open circuit
- Short circuit
- Series Circuit
- Parallel Circuit
- Series-Parallel Circuits
#1. D.C. Circuit.
The circuit in which direct current (D.C.) flows is known as the D.C. circuit.
The figure represents the D.C. circuit. Direct current (D.C.) is a unidirectional current whose magnitude remains constant. D.C. can be represented as shown below.
#2. A.C. Circuit.
The circuit in which alternating current flows is known as A.C. circuit. The simple A.C. circuit.
Alternating current is a bidirectional current, whose magnitude and direction changes periodically at regular intervals of time. The A.C. can be represented as shown below.
#3. Closed-Circuit.
Depending upon the condition of the circuit A.C. or D.C. circuits are classified into three circuits they are:
- Closed-circuit
- Open circuit
- Short circuit
In the closed circuit the current path is closed i.e. current starts from the positive terminal of the supply, through the line, load, neutral, and ends in the negative terminal of the supply.
#4. Open Circuit.
In an open circuit current won’t enter back to the negative terminal of the supply i.e. current path is incomplete due to the break in the circuit.
#5. Short Circuit.
The circuit in which line and neutral wires are shorted (touch each other) is known as a short circuit. Here current returns back directly to the negative terminal of the supply, without passing through the load.
#6. Series Combination of Resistances.
When the resistances are connected end-to-end, as shown in the figure, they are connected in series.
In the above figure resistance R1, R2, & R3 are connected in series, across a supply voltage of ‘V’ volts. in a series circuit current through each resistance is identical, the voltage drop across each resistance is different and the sum of voltage drops is equal to the voltage applied.
Since the voltage applied is equal to the sum of voltage drops across three resistances, the relation between V, V1, V2, and V3 is given by,
If R is the total resistance of the combination and I is the total current through the combination, then total voltage V=IR.
The above equation represents that the total or effective resistance of a series circuit is equal to the sum of all individual resistances connected in series.
Characteristics of a Series Combination of Resistances
- The equal current flows in all parts of the circuit.
- Individual resistors have their individual voltage drops.
- Voltage drops are addictive.
- The applied voltage is equal to the sum of individual voltage drops.
- Resistances are addictive.
- Powers are addictive.
#7. Parallel Combination of Resistances.
In a parallel combination of resistances, all the starting ends of resistances are connected to one common point and all finishing ends are connected to another common point.
Consider the above figure in which R1, R2, and R3, are connected between common points A & B across a supply voltage of V volts.
In parallel combination, the potential difference across all resistances is the same (i.e. V volts), the current in each resistor is different and is given by Ohm’s law and the total current (I) through the combination is the sum of individual currents through individual resistances.
If R is the total resistance of the combination, the total current I= V/R ∴ above expression becomes,
The above equation represents that the reciprocal of the total resistance of the circuit is equal to the sum of reciprocals of individual resistances connected in parallel.
Characteristics of a parallel combination of resistances
The main characteristics of a parallel circuit are:
- The voltage drop across each resistor is the same as the applied voltage.
- Individual resistors have their individual current.
- Branch current is additive.
- Conductance (1/R) is additive.
- Powers are additive.
- The total current is similar to the sum of the individual currents.
#8. Series-Parallel Combination of Resistances.
In this combination, resistances are connected in series as well as parallel.
To reduce such combinations to a simpler form the following steps are adopted :
- Find the effective resistance of the parallel combination of resistances.
- Replace the parallel combination with its equivalent resistance. Now-R1 is in series with the effective resistance of parallel combination.
- Determine the total resistance of the whole circuit.
If the circuit contains a series and parallel combination then the following steps are adopted :
- Find the effective resistance of the series combination of R2, R3, and R4.
- Replace the series combined with its equivalent resistance.
- Calculate the effective resistance of the whole circuit (i.e. parallel combination between R1, and effective resistance of R2, R3, & R4).