Exploring the Mysteries of Electric Fields

Electricity is all around us, and when harnessed, it lights our homes, powers our everyday appliances, and even keeps our bodies running. But what is electricity, and how does it actually work? At the core of it, it is something so incredible and essential in the world of physics and electromagnetism, which includes electric charges and the electric field that encompasses them.

Electric fields are vital to the understanding of numerous scientific and technological advancements of the modern world. Here, we will explore the nature of electric fields, the mechanisms by which they are generated, how to quantify them, and provide real-world examples that demonstrate their practical applications.

The blog covers:

1. What Is an Electric Field?

2. Interaction of Electric Fields with Charged Particles

3. Application

4. Conclusion

What Is an Electric Field?

To answer the question proposed in the introduction, electricity is the result of the presence and movement of an electric charge, and the presence of these charges produces an electric field.

An electric field is a physical field that surrounds charged particles and exerts a force between the particles. These charged particles can be stationary or in motion and can exist in the form of protons, electrons, or ions. Objects with a net non-neutral charge, meaning they are either positive or negative, will generate an electric field; this field can also be generated by changing magnetic fields, as described by Faraday's law of electromagnetic induction.

A charged object generates its own electric field, which will exert a force on the surrounding charged objects, creating a force between them that can be experienced as either an attraction or repulsion between the charged bodies-much like the behavior of magnets. This behavior must occur with two or more charged objects, as a single charge's electric field cannot exert a net force on itself.

It is important to note that a charge can only influence another charge in its surrounding space (Freedman et al., 2012, 699). Looking at Newton's second law, a body cannot exert a net force on itself, which means that a single charge cannot be affected by its own electric field (Freedman et al., 2012, 112). If this were not the case, we would be like cartoon characters and defy gravity by lifting ourselves to the sky by pulling up on our own belts.

Electric field is characterized by the equation:

E = F/q  (1)

where E represents the electric field's strength measured in newton per coulomb (N/C), F represents the force of the electric field experienced by a charged particle in N, and q is the charge of the particle in C. The electric field is a vector field, meaning it has both direction and magnitude.

The strength of the electric field is directly proportional to the charge of the source object and inversely proportional to the distance from the source object, again, much like the behavior of a magnet. Its direction is determined by the charge of the source object, and it can point in any direction in space.

Interaction of Electric Fields with Charged Particles

When a charged particle enters an electric field, the force it experiences is then characterized by the equation:

F = qE   (2)

where F, q, and E are represented by the force exerted by the electric field on the charged particle in N, the charge of the particle in C, and the electric field strength in N/C, respectively. The direction of the force is determined by the charge of the particle, and it can either be an attractive or repulsive force. This fundamental interaction between charged particles and electric fields forms the basis of many physical phenomena, from the behavior of lightning to the operation of electronic devices.

While the concept may seem new, we can draw other parallels to help solidify our understanding. Consider Equation 2 describing the electric force, and compare it to the well-known expression for gravitational force, F_g, exerted by the Earth on a mass, m₀ (Freedman et al., 2012, 700):

 F_g = m₀g (3)

where g is the acceleration due to gravity with the value of 9.8 m/s² (The National Institute of Standards and Technology, n.d.) and m₀ is the mass. From this equation, we are able to relate the force that a charged particle experiences when entering an electric field to the force that an object experiences when entering a gravitational field.

Application

Now that we have a general understanding of what an electric field is and how we can calculate it, let us explore some real-world applications of this knowledge. Since the discovery of electric fields, there have been extensive uses of this knowledge. They have been implemented in a wide range of industries and disciplines, from common printers to impressive particle accelerators, and even tissue engineering.

1. Inkjet printers rapidly squirt droplets of ink horizontally while utilizing an electric field to manipulate the droplets of ink to deposit them in the desired letters and images.

2. Particle accelerators, as the name implies, take advantage of electric fields to accelerate charged particles at extreme speeds, nearing the speed of light. These high-speed particles are then collided with a target or other particles traveling in the opposite direction. Through these experiments, we were able to discover the Higgs boson and quarks.

3. A surprising application for electric fields is in the field of medicine. There have been studies researching the use of electric fields for constructing artificial tissue. High electrical field generated in electrospinning causes the formation of nanofibers. Research is still being done in this field, and its results may revolutionize prosthesis.

Conclusion

The discovery of electric fields was fundamental in the field of physics and electromagnetism. With it, our understanding of the universe grew, and it opened an amazing avenue for innovation. Generated by charged particles, these fields possess an immense force that can significantly impact surrounding charged particles. Understanding how electric fields are generated, amazing technologies have been developed, not only in the seemingly simple inkjet printer but also in monumental particle accelerators and potentially lifesaving artificial tissue generation. The study of electric fields still has much to offer, and with it, we may learn more from the universe and how to advance humanity.

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References

The National Institute of Standards and Technology. (n.d.). CODATA Value: standard acceleration of gravity. Retrieved May 18, 2023, from https://physics.nist.gov/cgi-bin/cuu/Value?gn

Young, H. D., Ford, A. L., & Freedman, R. A. (2012). Sears and Zemansky's University Physics: With Modern Physics (A. L. Ford, Ed.). Addison-Wesley.

About the Author: Khoa Tran

Khoa Tran is an electrical engineer working at the Los Angeles Department of Water and Power and is currently pursuing his master's in electrical Power from the University of Southern California. He is fluent in both Vietnamese and English and is interested in outdoor activities and exploring new things.