electrical energy and power

Introduction

In many circumstances, it is required to assess the energy consumption of any electric equipment, such as the TV, refrigerator, oven, and washing machine in a home. And we pay the electric bill on a regular basis, and we can compute the amount of money payable for electricity consumption if we know how much electrical energy is utilised by our household equipment. As we all know, the energy used by a circuit or component is the time integral of the electric power. To learn about the energy consumption of any item, you must first understand electrical energy and power.

Electric Energy 

The energy used (or provided, depending on your point of view) in any given time period is given by PE = qV, where E is the electric energy, V is the voltage, and q is the amount of charge transferred in the time interval under consideration. 

By integrating across time, we may correlate total energy spent to power: Positive energy represents used energy, whereas negative energy represents energy production. It should be noted that a circuit element with a power profile that is both positive and negative over a given time period might consume or create energy depending on the sign of the integral of power. If the power remains constant throughout time, the energy may be represented simply as: E = Pt.

Formula

The formula of electric energy is:

Electric energy = P × t = V × I × t

Where, P = power, t = time, V = potential difference, I = current

Example

1. A light is wired to a wall outlet. Electric current flows from the wall outlet into the lamp’s light bulb, delivering electrical energy. Light energy is formed when the electric charges in the filament slow down to light the light bulb.
2. Cell phone batteries convert chemical energy into electric charges. The energy is used to move the electric charges. This electrical energy now travels through the phone, delivering electricity to it.
3. When our bodies break down food to form ATP energy, the ATP energy is converted into electrical energy. To generate our pulse, electric charges go via our particular nervous system cells.

Electric Power Definition

The rate at which work is done or energy is changed in an electrical circuit is defined as its power. Simply stated, it is a measure of how much energy is utilised in a certain period of time.

Current, or the flow of electric charge, and voltage, or the potential of charge to provide energy, are the two characteristics of electric power. Any combination of current and voltage values can produce a given amount of power.

P= QV/t =IV is the electric power generated in watts by an electric current I consisting of a charge of Q coulombs per t seconds passing through an electric potential (voltage) differential of V.

Electric Power Formula

The formula of Electric power is 

P=VI 

Where, V is the potential difference (volts), I is the electric current

Electric Power Rating

Every electrical appliance has a power rating, which indicates how much electricity it requires to function properly. This is usually expressed in watts (W) or kilowatts (kW), with 1000W equaling one kilowatt. Of course, the amount of electricity it consumes is determined by how long it is left turned on, and this is measured in kilowatt-hours (kWh). Energy is transferred from one kind to another by all electronic components. LEDs generating light, motors rotating, and batteries charging are all examples of energy exchanges that are desirable. Other energy exchanges are not ideal, but they are unavoidable. These undesired energy transfers are known as power losses, and they generally manifest themselves as heat. A component that loses too much power, or generates too much heat, might become highly unsatisfactory.

Even if the primary objective of a component is to transport energy, there will be losses to other kinds of energy. As a result of its other energy exchanges, LEDs and motors, for example, will still generate heat.

Most components have a maximum power dissipation rating, and it’s critical to maintain them running within that range. This will help you avoid “letting the magic smoke out,” as we lovingly refer to it. (Because cost savings are the primary concern of the operators, the first step is to attempt to reduce electrical energy losses in buildings, which is a challenging task. Aside from that, the electricity distribution network itself is a consumer of energy. Furthermore, if the network is not properly designed or tailored to meet the needs of its users, it will contribute to energy waste while also failing to meet their expectations in terms of power quality and availability. This is the avoid energy loss concept)

Difference Between Electric Energy and Electric Power

The difference between Electric energy and power is:

Joule’s Law VS Ohm’s Law 

James Prescott Joule, found the mathematical relationship between power dissipation and current through a resistance. This invention, which was published in 1841, followed the form of the previous equation () . It is known as Joule’s law, and it is the mathematical description of the rate at which resistance in a circuit converts electric energy into heat energy. A conductor between two points is subject to Ohm’s law, which states that the current through the conductor is directly proportional to the voltage across the two points.

These power equations, however, are so closely related to Ohm’s Law equations linking voltage, current, and resistance (E=IR ; I=E/R ; and R=E/I) that they are sometimes credited to Ohm.

Conclusion

The two qualities of electric power are current, or the passage of electric charge, and voltage, or the potential of charge to deliver energy. PE = qV, where E is the electric energy, V is the voltage, and q is the quantity of charge transferred in the time interval under consideration, gives the amount of energy being used (or provided, depending on your point of view) in any given time period. We can correlate total energy expended to power by integrating over time: Negative energy signifies energy production, whereas positive energy represents used energy.