What is the Difference Between Parallel and Series Connection

The key difference between parallel and series connection is that in a parallel connection, the components are connected across each other, forming exactly two sets of electrically common points, whereas a series connection has all components connected in an end-to-end manner, forming a single path for current flow.

We need different connection patterns when two or more electrical devices are connected in a circuit with an energy source. Parallel patterns and series patterns are two such major patterns. A parallel connection has all components sharing two common nodes. A series connection has all components connected in such a way that two components share the same node.

CONTENTS

1. Overview and Key Difference
2. What is a Parallel Connection
3. What is a Series Connection
4. Parallel vs Series Connection in Tabular Form
5. Summary – Parallel vs Series Connection

What is a Parallel Connection?

A parallel connection has all components sharing two common nodes. In this type of combination, the electronic devices are connected parallel to each other; therefore, all devices share the same two nodes. Moreover, the input voltage is always equal to the voltage across each device, and the electric current passing through the devices is shared between devices connected. Moreover, it requires a specific formula to get the equivalent resistance of this system.

We can summarize the details about voltage, current and resistance of a parallel connection as follows:

1. Voltage: equal across all components in a parallel circuit

E_total = E1 = E2 = E3 = ………

2. Current: the total circuit current equals to the sum of the current in an individual branch

I_total = I1 + I2 + I3 + ……….

3. Resistance: net resistance decreases upon addition of more components/devices

1/R_total = 1/R1 + 1/R2 + 1/R3 + ……

What is a Series Connection?

A series connection has all components connected in such a way that two components share the same node. In this type of combination, electronic devices are connected in-line with each other in an end-to-end connection pattern. Therefore, two devices always share the same node, but not all devices share the same two nodes as in a parallel connection.

Moreover, the input voltage is divided into series components, so the input voltage is not equal to the output that comes from a particular device in this connection. In addition, we can simply add the values of resistors to get the equivalent resistance of the system. The electric current that passes through each device does not have an effect on the electric current that passes, so it remains constant.

We can summarize the details about voltage, current and resistance of a series connection as follows:

1. Voltage: equal to the sum of the individual voltage drops

E_total = E1 + E2 + E3 + ……….

2. Current: same at each resistor

I_total = I1 = I2 = I3 = ………

3. Resistance: total resistance is equal to the sum of the individual resistances

R_total = R1 + R2 + R3 + ……..

What is the Difference Between Parallel and Series Connection?

A parallel connection has all components sharing two common nodes, while a series connection has all components connected in such a way that two components share the same node. The key difference between parallel and series connection is that in a parallel connection, the components are connected across each other, forming exactly two sets of electrically common points, whereas a series connection has all components connected in an end-to-end manner, forming a single path for current flow.

Moreover, in a parallel connection, the input voltage is always equal to the voltage across each device; however, in a series connection, the input voltage is not equal to the voltage across each device as the input voltage is divided into series components.

The below infographic presents the differences between parallel and series connection in tabular form for side by side comparison.

Summary – Parallel vs Series Connection

There are two major types of combinations of components in a connection of electrical devices. These are parallel connections and series connections. The key difference between parallel and series connection is that in a parallel connection, the components are connected across each other, forming exactly two sets of electrically common points, whereas a series connection has all components connected in an end-to-end manner, forming a single path for current flow.

Reference:

1. Thiele, Timothy. “An Overview of the Electrical Connections in and around Your Home.” The Spruce, The Spruce, 11 Nov. 2019.

Image Courtesy:

1. “Series and Parallel Circuit” By Brightyellowjeans – Own work (CC BY-SA 4.0) via Commons Wikimedia

2. “Physics-electricity-circuit” (CC0) via Pixabay