The behavior of a circuit totally depends upon the configuration of its circuit components. According to their connection configuration, these circuits are categorized as Parallel Circuit and Series Circuit. This post unfolds the meaning of a Parallel Circuit, how to make a Parallel Circuit, its various characteristics, applications, advantages and disadvantages.
What is a Parallel Circuit
A circuit is called a Parallel Circuit when two or more components are connected to the same node and both the sides of the components are connected directly to the battery or any other source. The current in a Parallel-Circuit has two or more paths to flow through it.
The most common example of Parallel-Circuit is the wiring of car headlights. In case the car headlights were in series, then if one of the lights fail, the other would also turn off which means the safety factor is lost.
Fig. 1 – Example of Car Headlights Connected in Parallel Circuit
How to Make a Parallel Circuit
Two or more circuit components are connected across a common voltage source to form a Parallel-Circuit. The figure below shows a typical Parallel-Circuit where the Resistors (R1, R2, R3, R4) are connected in parallel. Both the sides of the resistors are connected directly to the voltage source. The parallel path is called a branch and the voltage across all the branches are same but the current may be different.
Fig. 2 – Schematic Diagram of a Parallel Circuit
Characteristics of a Parallel Circuit
The primary characteristics of Parallel-Circuit are listed below:
Branch Currents in Parallel Circuit
According to Ohm’s law, I=E/R. This implies that each resistor in this circuit will draw current from the source. Hence, the total current drawn from the source is equal to the sum of the branch currents and the current flow in each path depends on the resistance of the branch. However, the voltage remains the same and creates potential difference across its terminals.
The total current (It) can be calculated using the equation,
It = I1+I2+I3+…. In
Where (I1+I2+I3+….In) are branch currents
Let us consider that the parallel-circuit is built with two resistors (R1 and R2) with different values (10 Ω and 5Ω) respectively. Voltage of 10V is applied across the resistors resulting in a current of 1A drawn from battery through R1 and 2A drawn through R2 which is derived from the equation I=E/R.
Hence, the two branch currents in the circuit are 1A and 2A which sums up to 3A.
It = 1+2 = 3A
Resistances in Parallel Circuit
The total resistances of any number of resistors is calculated using the equation,
Reciprocal of R1=1/R1=1/10=0.1
Reciprocal of R2=1/R2=1/5=0.2
Sum of the reciprocals above= 0.3
Rt= 1/0.3 = 3.33 Ω
Power in Parallel Circuit
Once the total current and the applied voltage values are known, Power can be calculated using the equation P=EI. In the example above, Applied Voltage (E)=10V and I=3A
∴P= 10 x 3 = 30 W
Applications of Parallel Circuit
The applications of Parallel Circuits include:
- The electrical wiring to the power points in every household is in the form of Parallel Circuits.
- The dc power supply in automobile industry uses Parallel Circuits.
- The computer hardware is designed using Parallel Circuits.
Advantages of Parallel Circuit
The advantages of Parallel Circuits include:
- Equal voltage is distributed to each component in the circuit.
- The current is not affected even when more components (resistors) are added or removed from the circuit.
Disadvantages of Parallel Circuit
The disadvantages of Parallel Circuits are listed below:
- It is more complicate to design compared to series circuits.
- Expensive to build.
- Short circuit can occur accidentally in parallel wiring and might be dangerous.
- Even if one of the component is faulty, the current can still pass through the circuit.