What is Electric Dipole? – Definition, Formula, Example

Welcome to this comprehensive guide on electric dipoles. In this article, we will delve into the definition, formula, and examples of electric dipoles. Whether you are a student of physics or simply curious about electricity, understanding electric dipoles is essential. So, let’s start by exploring the concept of an electric dipole. 

Definition of Electric Dipole

An electric dipole refers to a system composed of two equal and opposite charges separated by a small distance. These charges, also known as the positive and negative charges, exert both electrical and magnetic forces. The dipole is electrically neutral as the magnitudes of the two charges are equal. However, the presence of such a dipole leads to a non-uniform distribution of electric charge. 

Understanding Electric Dipole Moment

The electric dipole moment measures the strength or magnitude of an electric dipole. It is represented by the symbol “p” and is defined as the product of the charge magnitude (q) and the distance (d) separating the positive and negative charges. Mathematically, it can be expressed as: 

p = q * d 

The SI unit for the electric dipole moment is the coulomb-meter (C·m), which signifies the charge (in coulombs) multiplied by the distance (in meters). 

Electric Dipole Examples

Electric dipoles can be found in various objects and phenomena around us. Let’s explore a couple of examples to better understand their presence in everyday life. 

Example 1: Water Molecule 

One of the most common examples of an electric dipole is the water molecule (H2O). In a water molecule, the oxygen atom carries a partial negative charge, denoted as δ-, while the two hydrogen atoms carry partial positive charges, denoted as δ+. The unequal sharing of electrons between oxygen and hydrogen atoms creates a dipole moment within the molecule. This dipole moment is responsible for various properties of water, such as its high boiling point, surface tension, and ability to dissolve many substances. 

Example 2: Bar Magnet 

Although bar magnets are primarily associated with magnetic properties, they also exhibit electric dipole behavior. In a bar magnet, the north pole represents the positive region, while the south pole represents the negative region. This distribution of magnetic charge creates an electric dipole moment within the magnet. The concept of magnetic dipoles often helps in understanding the behavior and interaction of magnets in different scenarios. 

Electric Dipole Formula

Now that we have familiarized ourselves with electric dipoles, let’s explore the mathematical representation of their behavior. 

Electric Dipole Moment Formula

As mentioned earlier, the electric dipole moment (p) is the product of the charge magnitude (q) and the distance (d) separating the positive and negative charges. Mathematically, it can be represented as: 

p = q * d 


  • p represents the electric dipole moment, 
  • q denotes the charge magnitude, and 
  • d signifies the distance between the positive and negative charges. 

This formula provides a quantitative measure of the strength of the electric dipole and is crucial in various calculations and experiments involving electric fields. 

Electric Dipole Visualization and Diagram

To make things clearer, let’s draw a picture. Imagine a positive charge (+) and a negative charge (-) close to each other. Draw an arrow from the negative charge to the positive charge – that arrow represents the electric dipole moment. 

Electric Dipole Visualization and Diagram

Electric Potential Due to Dipole

Let’s assume the two charges “-q” placed at point A and “+q” placed at B. And the same points are separated by distance “d” to form a dipole. Then the electric potential is expressed as,

\(V= \frac{1}{4 \pi \epsilon } \frac{pcos \theta }{ r^{2} }\)

Behavior at 0 Degree Angle

In certain scenarios, the angle between the direction of the electric dipole moment and an external electric field becomes significant. Let’s examine what happens when the electric dipole moment and the electric field are perfectly aligned at a 0-degree angle. 

Mathematically it is represented as,

V = \(V= \frac{1}{4 \pi \epsilon } \frac{p }{ r^{2} }\)

Behavior When 90 Degrees

Now, picture the dipole moment arrow at a right angle (90 degrees) to the charges. It’s like they’re doing a side-step. This arrangement affects the dipole moment differently than when they are in perfect sync. 

in that case,

Electric potential, V=0

SI Units and Magnitude of Electric Dipole

Just like we measure distance in meters and weight in kilograms, the SI unit for the electric dipole moment is a coulomb meter (C·m). To find the magnitude, use the formula p = q * d. This way, we can measure and compare different electric dipoles. 

Electric Dipole Formula Derivation

Don’t be scared by the word “derivation” – it’s just a fancy way of explaining how we get the formula. Imagine breaking down a dance move step by step. Similarly, we break down the dipole moment formula to understand how it comes together. 

Dipole Moment in Uniform Electric Field

Now, let’s explore how our dipole behaves in a uniform electric field. It’s like our dancing duo entering a dance floor with a specific pattern – the uniform electric field. Understanding this helps us see how dipoles interact in different situations. 

Physical Significance of Electric Dipole

Electric dipoles are not just theoretical – they’re practical too! They play a role in many technologies and everyday devices. Understanding their physical significance helps us appreciate their importance in our lives. 


In conclusion, electric dipoles play a fundamental role in understanding electrical and magnetic phenomena. By comprehending the definition, formula, and examples of electric dipoles, you can gain insights into various natural phenomena and technological applications. Remember that the electric dipole moment provides a measure of the strength of the dipole, while the behavior at different angles and in different electric fields offers valuable insights into the physical significance and behavior of electric dipoles. 

Explore more about electric dipoles and uncover the wonders of electricity and magnetism. Now that you possess a comprehensive understanding of electric dipoles, it’s time to delve deeper into this fascinating subject and witness its impact in the world around us. 

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Define Electric Dipole Moment

The electric dipole moment is like an arrow that shows the strength and direction of a pair of electric charges. It’s the way we summarize the influence of positive and negative charges dancing together. 

Define Electric Dipole

An electric dipole is a pair of electric charges – one positive and one negative – that are close to each other. They work together, creating a dance that we call an electric dipole. 

What is the Direction of Electric Dipole?

The direction of an electric dipole is indicated by the electric dipole moment arrow, which points from the negative charge to the positive charge. It’s like a guide that shows us how the charges are dancing together. 

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