Windmills For Electricity Explained


windmills for electricity

Windmills for electricity use wind energy to generate clean, renewable power. These wind turbines convert kinetic energy into electrical energy, reducing carbon emissions and dependence on fossil fuels. 

 

What are Windmills for Electricity?

Windmills for electricity are modern devices that transform kinetic wind energy into electrical power.

✅ Harness renewable energy for clean power

✅ Reduce carbon footprint and dependence on fossil fuels

✅ Support sustainable power generation worldwide

Windmills for electricity are part of a broader shift toward renewable energy, providing clean alternatives to fossil fuels for homes, businesses, and utilities.

 

History of Windmills

Windmills for electricity - Mankind has been harnessing the wind's energy for many years. From Holland to traditional farms around the world, windmills were used in the past for pumping water through primitive irrigation systems or to grind grain. Then, the wind turned large "sails" that were connected by a long vertical shaft, which was attached to a grinding machine or a wheel that turned and drew water from a well. Today's turbines harness the energy of the wind to turn large metal blades, which in turn spin a generator that produces electric power. Alongside wind, other renewable energy sources like solar, biomass, and tidal energy are shaping a diversified and sustainable energy future.

From the mid-1970s to the mid-1980s, the United States government collaborated with industry to advance windmill technology for power generation and enable the development of large commercial wind turbines. NASA led this effort at the Lewis Research Center in Cleveland, Ohio, and it was an extraordinarily successful government research and development activity.

 

National Science Foundation

With funding from the National Science Foundation and later the Department of Energy (DOE), a total of 13 experimental wind turbines were put into operation, including four major wind turbine designs. This research and development program pioneered many of the multi-megawatt turbine technologies in use today, including steel tube towers, variable-speed generators, composite blade materials, partial-span pitch control, as well as aerodynamic, structural, and acoustic engineering design capabilities. The large Windmills For Electricity developed under this effort set several world records for diameter and power output. The Mod-2 wind turbine cluster produced a total of 7.5 megawatts of power in 1981. Government incentives, such as alternative energy tax credits, have played a major role in expanding wind power adoption across North America.

 

Wind Turbine Technology

In 1987, the Mod-5B was the largest single wind turbine operating in the world with a rotor diameter of nearly 100 meters and a rated power of 3.2 megawatts. It demonstrated an availability of 95 percent, an unparalleled level for a new first-unit wind turbine. The Mod-5B featured the first large-scale variable-speed drive train and a sectioned, two-blade rotor, which enabled easy transport of the blades.

Later, in the 1980s, California provided tax rebates for ecologically harmless wind turbines. These rebates helped fund the first major deployment of wind power for the utility grid. These turbines gathered in large wind parks such as at Altamont Pass, would be considered small and uneconomical by modern wind power development standards.

In the 1990s, as aesthetics and durability became more important, turbines were placed atop steel or reinforced concrete towers. Small generators are connected to the ground tower, and then the tower is raised into position. Larger generators are hoisted into position atop the tower, and a ladder or staircase is located inside the tower to allow technicians to reach and maintain the generator.

Originally, wind turbines were built right next to where their power was needed. With the availability of long-distance electric power transmission, wind generators are now often on wind farms in windy locations, and huge ones are being built offshore, sometimes transmitting power back to land using high-voltage submarine cable. Since wind turbines are a renewable means of generating power, they are being widely deployed, but their cost is often subsidized by taxpayers, either directly or through renewable energy credits. Much depends on the cost of alternative energy sources. The cost of wind generators per unit of power has been decreasing by about 4% per year.

 

Modern Wind Turbines

The most modern generations of Windmills for electricity are more properly called wind turbines, or wind generators, and are primarily used to generate electric power. Modern windmills are designed to harness the energy of the wind and convert it into electric energy. The largest wind turbines can generate up to 6 MW of power (for comparison, a modern fossil fuel power plant generates between 500 and 1,300 MW). Many large-scale renewable energy projects now combine wind farms with solar and storage systems, ensuring reliable, clean power for communities worldwide.

Small wind turbines can generate as little as a few kilowatts, while larger models produce up to 100 kilowatts or more, depending on design and location. These devices capture moving air, and as wind turbines operate, the kinetic energy generated can be used directly or sent into the electrical grid. On a utility scale, wind farms combine many large turbines to deliver massive amounts of energy, powering thousands of homes and businesses. This range of applications, from residential to industrial, demonstrates the versatility of wind technology in meeting diverse energy needs.

Related News

Electricity Prices Explained

Electricity prices reflect tariffs, kWh rates, time-of-use schedules, peak demand charges, and grid congestion, driven by generation costs, transmission losses, and load profiles in power systems and industrial electrical engineering.

 

The Complete Guide to Electricity Prices

Electricity prices, or rates, are usually determined by electric utilities and the governmental organizations that oversee them. The fees an electric utility company charges its customers for service aer based on electricity prices set by government, except in the case where they cost electricity prices on a deregulated basis. In that case, electricity prices are determined by marketplace factors such as supply and demand. Electric utility companies charge their customers different rates, depending on the type of customer, the kind of contract, and on the customer's needs. Electricity Prices bill energy on the kwh basis of the individual customer's rate, the level of consumption, and other charges, such as taxes and fuel adjustments. This is how electricity billed. For a deeper breakdown of typical rate components, resources like electricity cost guides explain line items and surcharges clearly.

That collection of rates is called a tariff. The power tariff is designed to provide the privately owned electric utility with enough income to allow investors to earn a cash return and cover operation and maintenance costs. Most of the larger utilities operate as regulated franchises, meaning that the prices they charge are subject to public review, often by a State public utility commission. In competitive markets, customers may choose an electricity supplier while the utility still handles delivery services and billing oversight.

Publicly owned electric utilities are nonprofit, local government agencies established to provide service to their communities and nearby consumers at cost, returning excess funds to the consumer in the form of community contributions, more economic and efficient facilities, and lower power rates. To meet these community objectives, public power agencies plan their electricity supply over multiyear horizons to manage risk and affordability.

Publicly owned electric utilities (which number approximately 2,000) include municipals, public power districts, State authorities, irrigation districts, and other State organizations. Some of these organizations also own or contract for electricity generation assets to enhance self-sufficiency and rate stability.

There are approximately 900 cooperative electric utilities in the United States currently doing business in 47 States. These utilities are owned by their members and are established to provide power to those members. Because member education supports better usage decisions, many cooperatives provide primers on what electricity is and how it is measured on bills.

Average retail Electricity prices of power are calculated by dividing utility revenue by retail sales. The resulting measurement is the cost, or average revenue per kilowatthour, of power sold. (A kilowatthour is equal to one watt of power supplied to an electric circuit steadily for 1,000 hours.) Electric utilities usually offer three primary classes of service: residential, commercial, and industrial. The average price per kilowatthour for residential consumers is generally higher than for any other sector due in part to higher costs associated with serving many consumers who use relatively small amounts of power. In Ontario, the industrial sector has the lowest energy prices and energy bills rates every month due to the economies of serving a few consumers who use relatively large amounts of electricity. Understanding the distinction between energy in kilowatthours and instantaneous electricity power demand helps customers interpret peak charges and capacity fees. Regional consumption patterns, including trends in electricity demand in Canada, can influence wholesale prices and cross-border power flows affecting local rates.

 

average retail

 

Related Articles

View more

Electricity Power Explained

Electricity power underpins voltage, current, and wattage in generation, transmission, and distribution across the grid, integrating AC/DC systems, transformers, generators, load management, power factor correction, and renewable energy for efficient, reliable supply.

 

Electricity Power: Real-World Examples and Uses

The make up of the electricity power sector has been in transition over recent history. In most provinces, there has been a transition from traditional electric utilities (which are mostly provincially-owned crown corporations) to private generation, transmission and distribution assets. For context, industry overviews such as electricity generation in Canada outline how policy and market structures influence capacity additions today.

In 2014, Canadian eutilities and industrials generators produced more than 639 terawatt hours of electricity. When it comes to hydroelectric power, Canada is the world's second largest producer. Hydroelectricity accounts for 59.3 per cent of Canada’s supply. Other energy sources that contribute to the transfer of energy include: coal, uranium, natural gas, petroleum and non-hydro renewable energy sources. About 67 per cent of Canada’s energy comes from renewable sources like wind, solar and hydroelectric power stations and 82% from non-greenhouse gas emitting sources. A breakdown of major fuels is available through sources of electricity for readers comparing provincial mixes.

Hydropower output is intrinsically linked to water availability and operations, and resources on water and electricity explain how hydrology and infrastructure shape generation profiles.

In 2014, almost 59 terawatt hours of electricity exported to the USA, while about 13 terawatt hours was imported from the United States. These trade patterns reflect how provinces balance load and generation portfolios, as noted in discussions of electricity supply dynamics under varying market conditions.

Canada's industrial sector is responsible for the largest share of electricity demand because there are a number of energy-intensive industrial activities like mining, oil and gas production, pulp and paper production, and other primary industry uses. Residential and commercial sectors consume much smaller quantities of electricity for lighting (light bulb), heating, and communications. Detailed consumption patterns can be explored in Canada's electricity demand by sector and region.

R&D programs aimed at maintaining the operating capability of the nation’s existing nuclear power plants and developing the next generation of nuclear technologies. Nuclear energy is the world’s largest source of emission-free electricity power. The Nuclear Energy program is working to develop cost-efficient technologies that further enhance nuclear safety, minimize the generation of nuclear waste, and further reduce the risk of proliferation. Within the broader generation portfolio, resources like nuclear are profiled in guides on how electricity is generated across different technologies.

To meet the rising demand of the 21st century, significant improvements in America’s electric system are necessary. Blackouts serve as a powerful reminder of the critical role electricity plays in the everyday lives of people.

 

Voltages, currents, power energy

When it comes to electric current, electrical voltage, electric circuit dynamics and energy powers, all rely on the flow of the electron. What this means is that power voltage feeds loads, solid state power load devices, and other loads that need electric power. Electric power is the rate at which that power is measured in watts or voltage in volts. There are various forms of energy measured in si unit: apparent power, reactive power, ac power, real power in watts, etc. For a refresher on fundamental concepts and terminology, see what is electricity to connect these quantities with practical applications.

Electrical Engineers and Scientists alike seek common views in order to develop new technologies for the storage of energy and the transmission of electric potential through power circuits that will contribute to energy efficiency of the electric industry. For instance, the copper wires used in typical transmission lines lose a percentage of the electricity passing through them because of resistance over long distances, which causes the wires to heat up. But "superconducting" materials have no resistance, and if they are used to transmit electricity in the future, very little of the electricity will be lost.

 

Related Articles

View more

Home Electricity - Electrical Energy Information

Home electricity powers lighting, appliances, and electronics using energy from the grid or renewable sources like solar. Understanding usage, safety, and efficiency helps reduce costs and improve performance in daily life.

 

What is Home Electricity?

Home electricity refers to the power used to operate household systems and devices.

✅ Powers lights, appliances, HVAC, and electronics

✅ Supplied by utilities or solar energy systems

✅ Measured in kilowatt-hours and billed monthly

 

How Electricity Enters and Flows Through Your Home

Electricity originates from a distant power station, fueled by coal, natural gas, nuclear power, or renewable sources, and is transformed into high-voltage energy for long-distance transmission. Along the way, transformers step this voltage down to safe, usable levels. When it reaches your home, the electricity flows through a service line to a main panel, where circuit breakers distribute it to branch circuits that power every room and outlet.

In the United States, most residential circuits provide about 120 volts of alternating current (AC) at 60 Hz. Voltage measures the energy per unit charge: 120 volts means 120 joules of energy are transported by each coulomb of charge. One coulomb per second equals one ampere, so an appliance drawing 1 ampere at 120 volts consumes energy at 120 watts—120 joules per second.

 

How Appliances Use Electrical Energy

When you switch on an appliance, it allows 120 volts of potential to push current through the device—similar to using water pressure to move water through a pipe. As electric charge flows, energy is transformed into useful work like heating, lighting, or mechanical motion. Voltage gradually drops to nearly zero by the time the current exits the appliance.

This “spent” charge is carried back to your electrical panel via the neutral wire and ultimately to the ground through the grounding system. The ground serves as a vast reservoir, stabilizing voltages and protecting users in the event of a fault.

 

Understanding Home Wiring and Safety

In a standard polarized receptacle, the smaller prong connects to the hot wire (120 volts), and the wider prong to the neutral (0 volts). The hot wire delivers the current; the neutral completes the circuit back to the panel. A separate ground wire exists for safety—it’s not part of the working circuit but protects against electric shock if a fault occurs.

Most wall outlets contain two receptacles (a duplex) wired in parallel. This means two appliances plugged in will receive the same 120-volt supply but can draw different amounts of current. Parallel wiring is standard throughout the home, allowing consistent voltage distribution while accommodating various electrical loads.

 

Where the Energy Comes From and Where It Goes

Electricity used at home ultimately comes from generators that elevate the voltage of electric charge before it travels across the grid. After powering your home, the now low-energy charge returns to the ground. This closed-loop system—from the earth to the generator and back—enables efficient energy use and the safe disposal of spent charge.

Whether your electricity comes from traditional utilities or rooftop solar panels, the underlying principles remain the same: raise voltage at the source, deliver it efficiently, use it safely, and return it to ground. Understanding these concepts helps homeowners stay informed, reduce waste, and use electricity more safely and effectively.

 

Related Articles

 

 

View more

Electromagnetic Induction

Electromagnetic induction is the process of generating electric current by changing a magnetic field, forming the basis for transformers, generators, and electric motors in power generation and energy conversion systems.

 

What is Electromagnetic Induction?

Electromagnetic induction is a fascinating and vital concept shaping how we generate, transfer, and utilize electricity.

✅ Process where a changing magnetic field induces an electric current in a conductor

✅ Fundamental principle behind transformers, generators, and electric motors

✅ Essential for modern power generation, transmission, and energy conversion

 

Its underlying principles, Faraday's Law and Lenz's Law, explain the phenomena occurring when magnetic fields interact with conductors. At the same time, its various applications, such as electric generators, transformers, induction heating, and wireless charging, have revolutionized our daily lives. As we continue to explore and understand this intricacy, we can look forward to even more innovations and advancements in electricity and magnetism. Understanding Faraday's Law is essential to grasp how changing magnetic fields generate electricity through electromagnetic induction.

 


 

Fundamental Laws of Electromagnetic Induction

Faraday's Law of electromagnetic induction, invented by Michael Faraday, is a key principle that states that the induced EMF in a coil is proportional to the rate of change of the magnetic flux (dφ/dt) passing through the coil. The more rapidly the magnetic field changes, the higher the amount of voltage induced will be. This relationship between electricity and magnetism laid the foundation for the development of various electrical devices and systems. The relationship between electricity and magnetism forms the foundation of generators, transformers, and other key electrical systems.

Lenz's Law, another crucial principle, explains the direction of the induced current. It states that the induced current will always flow in a direction that opposes the change in magnetic flux, acting as a stabilizing electromotive force. By combining Faraday's and Lenz's Law, we can better understand how it operates in real-world applications. For a deeper understanding of how voltage is produced in coils, explore the principles of Lenz's Law.

 

Core Applications: Generators and Transformers

One notable application is the electrical generator, which converts mechanical energy into electrical energy. In a typical generator, a coil of wire rotates within a magnetic field, creating a changing magnetic flux. This change induces a voltage and current in the coil, generating electricity. Generators are commonly used in power plants, automobiles, and other devices requiring a continuous electrical supply. A three-phase transformer uses electromagnetic induction to efficiently transfer power between circuits at different voltages.

Another critical application is the transformer, which transfers electrical energy between circuits with different voltages. Transformers consist of two induction coils wrapped around a shared magnetic core. When an alternating current flows through the primary coil, it creates a magnetic field that induces a voltage in the secondary coil. By adjusting the number of turns in the coils, transformers can step up or down the voltage as needed for specific electrical systems.

 

Special Phenomena: Eddy Currents, Mutual Inductance, and Self-Inductance

Eddy currents are an intriguing aspect of electromagnetic induction. These currents form when a magnetic field changes, causing swirling, closed loops of electric current within a conductor. Eddy currents generate heat and can lead to energy losses in electrical systems, but they also have practical applications, such as in metal detectors and induction heating. Devices that use electromagnetic induction, such as electric motors, rely on core principles of inductance to regulate energy transfer.

Two critical aspects of electromagnetic induction are mutual inductance and self-inductance. Mutual inductance occurs when the current in one coil induces a voltage in a nearby coil due to their shared magnetic field. Self-inductance refers to a coil's ability to induce a voltage within itself when the current flowing through it changes. Understanding these concepts is crucial for designing and analyzing complex electrical circuits and systems.

 

Demonstrating the Principle: Coil and Magnet Interaction

In many cases, it involves the interaction of a coil and a magnet, either a permanent magnet or an electromagnet. A bar magnet, for example, may be moved near a coil, or the coil may be moved about the magnet. This motion changes the magnetic field and induces a voltage in the coil, demonstrating the dynamic relationship between electricity and magnetism. Learning the basics of electrical resistance helps explain how eddy currents generate heat in conductive materials.

 

Modern Impact and Emerging Technologies

It has an immense impact on modern life, from generating electricity in power plants to operating devices like transformers, electric motors, and wireless chargers. The principles of Faraday's Law and Lenz's Law help explain the complex phenomena that occur when magnetic fields interact with conductors. By harnessing these principles, scientists and engineers have created various practical applications that have revolutionized our daily lives.

Electromagnetic induction demonstrates the fundamental relationship between electricity and magnetism and is integral to many aspects of our modern world. Faraday's Law and Lenz's Law underpin this phenomenon, governing the induced voltage and current when magnetic fields change. The applications of electromagnetic induction range from electric generators and transformers to the study of eddy currents, mutual in influence and self-inductance. By understanding these principles, we can continue to innovate and develop new technologies to improve our daily lives and advance our understanding of the world.

 

Induction Heating

Electromagnetic induction heating is another practical application that relies on electromagnetic induction. This technology utilizes eddy currents to heat conductive materials, such as metals. By placing a conductive material within a rapidly changing magnetic field, eddy currents are generated within the material, producing heat due to their resistance. This heating method has been employed in various industrial processes, including metal hardening, welding, and cooking.

Wireless charging is an emerging technology that utilizes electromagnetic induction to transfer energy between two coils. When an electric current flows through the primary coil, it generates a magnetic field, which induces a voltage in the secondary coil, providing power to the device. This technology has seen increasing adoption in recent years, particularly for charging electric vehicles and smartphones, offering convenience and reduced dependence on cords and cables.

 

Related Articles

 

View more

Electricity Terms Explained

Electricity terms explain voltage, current, resistance, impedance, power factor, frequency, AC/DC, circuits, transformers, and load. Master key definitions to analyze systems, size conductors, mitigate harmonics, and ensure safety compliance.

 

Understanding Electricity Terms in Electrical Safety

Here are the top 50 commonly used electricity terms that are essential for understanding electrical systems, devices, and concepts: For a broader glossary with context and examples, see the curated list at Electrical Terms by Electricity Forum for deeper reference.

Voltage (V) – The electrical potential difference between two points in a circuit. Understanding how potential difference relates to the nature of electricity is clarified in this overview of what electricity is and how it behaves.

Current (I) – The flow of electric charge, measured in amperes (A). A concise explanation of electricity as a physical phenomenon is given in this definition of electricity for foundational understanding.

Resistance (R) – Opposition to current flow, measured in ohms (Ω).

Power (P) – The rate of doing work or transferring energy, measured in watts (W).

Ohm's Law – The relationship between voltage, current, and resistance. For a step-by-step refresher on the relationships among voltage, current, and resistance, explore this basic electricity guide to connect theory with practical examples.

Alternating Current (AC) – Electric current that reverses direction periodically.

Direct Current (DC) – Electric current that flows in one direction only. For a side-by-side comparison of waveform behavior, applications, and conversion methods, review the differences between AC and DC to strengthen conceptual understanding.

Frequency (f) – The number of cycles per second in AC, measured in hertz (Hz).

Impedance (Z) – The total opposition to current flow in an AC circuit, combining resistance and reactance, measured in ohms.

Capacitance (C) – The ability to store electrical energy in an electric field, measured in farads (F).

Inductance (L) – The ability of a conductor to induce a voltage when current changes, measured in henries (H).

Power Factor (PF) – The ratio of real power to apparent power, indicating the efficiency of a system.

Real Power (P) – The actual power consumed to perform work, measured in watts.

Apparent Power (S) – The total power in a system, combining real and reactive power, measured in volt-amperes (VA).

Reactive Power (Q) – Power in AC circuits that does not perform useful work, measured in volt-amperes reactive (VAR).

Load – The device or equipment that consumes electrical power.

Short Circuit – An abnormal connection between two points in a circuit, causing excessive current flow. To ground this topic in fundamentals, revisit what an electrical circuit is before examining fault conditions.

Overload – A condition where a circuit or device exceeds its rated current capacity.

Circuit Breaker – A protective device that interrupts the flow of current when an overload or short circuit occurs.

Fuse – A protective device that melts to break the circuit when excessive current flows.

Grounding (Earthing) – Connecting parts of an electrical system to the Earth to ensure safety.

Transformer – A device that transfers electrical energy between two or more circuits through electromagnetic induction.

Conductor – A material that allows the flow of electrical current, typically copper or aluminum.

Insulator – A material that resists the flow of electric current, such as rubber or plastic.

Phase – The distribution of alternating current electricity into separate waveforms, often used in three-phase power systems.

Watt (W) – The unit of power, equivalent to one joule per second.

Kilowatt (kW) – A unit of power equal to 1,000 watts.

Megawatt (MW) – A unit of power equal to 1 million watts.

Voltage Drop – The reduction in voltage across a component or conductor in an electrical circuit.

Arc Flash – A dangerous condition associated with the release of energy caused by an electric arc.

Resistor – A component that opposes the flow of current, used to control voltage and current in circuits.

Diode – A semiconductor device that allows current to flow in one direction only.

Rectifier – A device that converts AC to DC.

Inverter – A device that converts DC to AC.

Contactor – An electrically controlled switch used to control a power circuit.

Relay – A switch operated by an electromagnet, used for controlling circuits.

Switchgear – Equipment used to switch, control, and protect electrical circuits.

Distribution System – The system of wires and equipment that delivers electricity from substations to consumers.

Neutral – A conductor that carries current back to the source in an electrical system.

Busbar – A conductor used to distribute power from one source to multiple circuits.

Overcurrent Protection – Devices like fuses and circuit breakers designed to protect circuits from excessive current.

Phase Angle – The angular displacement between voltage and current waveforms in AC circuits.

Power Supply – A device that provides the necessary electrical power to a circuit or device.

Generator – A device that converts mechanical energy into electrical energy. This ties directly to how electrical energy is produced, transferred, and ultimately consumed.

Motor – A device that converts electrical energy into mechanical energy.

Frequency Converter – A device that changes the frequency of AC power.

Power Grid – A network of transmission lines, substations, and power stations for distributing electricity.

Service Panel – The central distribution point for electrical circuits in a building, containing circuit breakers or fuses.

Utility Transformer – A transformer that steps down high voltage for distribution to consumers.

Harmonics – Distortions in the electrical waveform that can affect power quality.

These terms cover a wide range of concepts from basic electrical theory to components and safety practices in electrical systems.
 

 

Related Articles

View more

Electricity and Magnetism - Power Explained

Electricity and magnetism are interconnected forces forming electromagnetism, which explains electric currents, magnetic fields, and their interactions. These principles power motors, generators, transformers, and more in modern electrical and magnetic systems.

 

What is: "Electricity and Magnetism"

Electricity and magnetism are fundamental forces in physics that form the basis of electromagnetism.

✅ Describe how electric charges and magnetic fields interact in nature and technology

✅ Underlie the function of motors, transformers, and generators

✅ Explain current flow, induction, and electromagnetic waves

Electricity - What is it?

Electricity is a form of energy that is transmitted through copper conductor wire to power the operation of electrical machines and devices, including industrial, commercial, institutional, and residential lighting, electric motors, electrical transformers, communications networks, home appliances, and electronics.

When charged particles flow through the conductor, we call it "current electricity". This is because when the charged particles flow through wires, electricity also flows. We know that current means the flow of anything in a particular direction. For example, the flow of water. Similarly, the flow of electricity in a specific direction is referred to as an electric current. The interplay of charge, field, and force is explored in what is electric load, covering how power is delivered in electromagnetic systems.

When an electric current flows, it produces a magnetic field, a concept closely tied to Faraday's Law of Induction, which underpins much of modern electrical engineering.

 

Magnetism  - What is it?

Magnetism is a type of attractive or repulsive force that acts up to certain distance at the speed of light. The distance up to which this attractive or repulsive force acts is called a "magnetic field". Magnetism is caused by the moving electric charges (especially electrons). When two magnetic materials are placed close to each other, they experience an attractive or repulsive force. To understand magnetic field strength and units, our magnetic induction basics in induction page discusses flux and Teslas.


What is the relationship between electricity and magnetism?

In the early days, scientists believed that there were two uniquely separate forces. However, James Clerk Maxwell proved that these two separate forces were actually interrelated.

In 1820, Hans Christian Ørsted observed a surprising phenomenon: when he switched on the battery from which the electric current was flowing, the compass needle moved away from the north pole. After this experiment, he concluded that the electric current flowing through the wire produces a magnetic field.

Electricity and magnetism are closely related to each other. The electric current flowing through the wire produces a circular magnetic field outside the wire. The direction (clockwise or counterclockwise) of this magnetic field depends on the direction of the electric current.

Similarly, a changing magnetic field generates an electric current in a wire or conductor. The relationship between them is called electromagnetism.

Electricity and magnetism are interesting aspects of electrical sciences. We are familiar with the phenomenon of static cling in our everyday lives - when two objects, such as a piece of Saran wrap and a wool sweater, are rubbed together, they cling.

One feature of this that we don't encounter too often is static "repulsion" - if each piece of Saran wrap is rubbed on the wool sweater, then the pieces of Saran wrap will repel when brought near each other. These phenomena are interpreted in terms of the objects acquiring an electric charge, which has the following features:

  • There are two types of charge, which by convention are labelled positive and negative.

  • Like charges repel, and unlike charges attract.

  • All objects may have a charge equal to an integral number of a basic unit of charge.

  • Charge is never created or destroyed.

To explore how electric and magnetic forces interact at a distance, see what is static electricityis, which includes examples like static cling and repulsion.

 

Electric Fields

A convenient concept for describing these electric current and magnetic current forces is that of electric field currents. Imagine that we have a fixed distribution of charges, such as on the plate below, and bring a test charge Q into the vicinity of this distribution.

 

img134 
 

Fig. 1 Test charge in the presence of a fixed charge distribution

This charge will experience a force due to the presence of the other charges. One defines the electric field of the charge distribution as:


img135

The electric field is a property of this fixed charge distribution; the force on a different charge Q' at the same point would be given by the product of the charge Q' and the same electric field. Note that the electric field at Q is always in the same direction as the electric force.

Because the force on a charge depends on the magnitude of the charges involved and the distances separating them, the electric field varies from point to point, both in magnitude and direction.

By convention, the direction of the electric field at a point is the direction of the force on a positive test charge placed at that point. An example of the electric field due to a positive point charge is given below. 


img136

Fig. 2: Electric field lines of a positive charge

 

Power and Magnetic Fields

A phenomenon apparently unrelated to power is electromagnetic fields. We are familiar with these forces through the interaction of compasses with the Earth's magnetic field, or the use of fridge magnets or magnets on children's toys. Magnetic forces are explained in terms very similar to those used for electric forces:

  • There are two types of magnetic poles, conventionally called North and South
  • Like poles repel, and opposite poles attract

However, this attraction differs from electric power in one important aspect:

  • Unlike electric charges, magnetic poles always occur in North-South pairs; there are no magnetic monopoles.

Later on we will see at the atomic level why this is so.

As in the case of electric charges, it is convenient to introduce the concept of a magnetic field in describing the action of magnetic forces. Magnetic field lines for a bar magnet are pictured below.

img137
 

Fig. 3: Magnetic field lines of a bar magnet

One can interpret these lines as indicating the direction that a compass needle will point if placed at that position.

The strength of magnetic fields is measured in units of Teslas (T). One tesla is actually a relatively strong field - the earth's magnetic field is of the order of 0.0001 T.

 

Magnetic Forces On Moving Charges

One basic feature is that, in the vicinity of a magnetic field, a moving charge will experience a force. Interestingly, the force on the charged particle is always perpendicular to the direction it is moving. Thus, magnetic forces cause charged particles to change their direction of motion, but they do not change the speed of the particle.

This property is utilized in high-energy particle accelerators to focus beams of particles, which ultimately collide with targets to produce new particles, including gamma rays and radio waves.

Another way to understand these forces of electricity and magnetism is to realize that if the force is perpendicular to the motion, then no work is done. Hence, these forces do no work on charged particles and cannot increase their kinetic energy.

If a charged particle moves through a constant magnetic field, its speed stays the same, but its direction is constantly changing. A device that utilizes this property is the mass spectrometer, which is used to identify elements. A basic mass spectrometer is pictured below.

 

img145
 

Figure 4: Mass spectrometer

In this device, a beam of charged particles (ions) enters a region of a magnetic field, where they experience a force and are bent in a circular path. The amount of bending depends on the mass (and charge) of the particle, and by measuring this amount one can infer the type of particle that is present by comparing it to the bending of known elements.

 

Magnet Power From Electric Power

A connection was discovered (accidentally) by Orsted over 100 years ago, when he noticed that a compass needle is deflected when brought into the vicinity of a current-carrying wire. Thus, currents induce magnetic fields in their vicinity. An electromagnet is simply a coil of wires which, when a current is passed through, generates a magnetic field, as below.

 

img149
 

Figure 5: Electromagnet

Another example is in an atom, where an electron is a charge that moves around the nucleus. In effect, it forms a current loop, and hence, a magnetic field may be associated with an individual atom. It is this basic property which is believed to be the origin of the magnetic properties of various types of materials found in nature.

Maxwell's equations (also known as Maxwell's theory) are a set of coupled partial differential equations that, together with the Lorentz force law, form the foundation of classical electromagnetism, which deals with electromagnetic radiation, electromagnetic waves, and electromagnetic force.  For a deeper understanding of the magnetic effects of electrical current, our article on electromagnetic induction explains how magnetic fields can generate electricity in conductors.

 

Related Articles

 

View more

Sign Up for Electricity Forum’s Newsletter

Stay informed with our FREE Newsletter — get the latest news, breakthrough technologies, and expert insights, delivered straight to your inbox.

Electricity Today T&D Magazine Subscribe for FREE

Stay informed with the latest T&D policies and technologies.
  • Timely insights from industry experts
  • Practical solutions T&D engineers
  • Free access to every issue

Download the 2025 Electrical Training Catalog

Explore 50+ live, expert-led electrical training courses –

  • Interactive
  • Flexible
  • CEU-cerified