# What is Electrical energy: Definition and 124 Discussions

Electrical energy is energy derived as a result of movement of electrons. When used loosely, electrical energy refers to energy that has been converted from electric potential energy. This energy is supplied by the combination of electric current and electric potential that is delivered by an electrical circuit (e.g., provided by an electric power utility). At the point that this electric potential energy has been converted to another type of energy, it ceases to be electric potential energy.
Thus, all electrical energy is potential energy before it is delivered to the end-use. Once converted from potential energy, electrical energy can always be called another type of energy (heat, light, motion, etc.).
Electrical energy is usually sold by the kilowatt hour (1 kW·h = 3.6 MJ) which is the product of the power in kilowatts multiplied by running time in hours. Electric utilities measure energy using an electricity meter, which keeps a running total of the electric energy delivered to a customer.

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1. ### How much electrical energy can be extracted from Iron in a cell?

Hi, I am trying to get to an answer for the following scenario. Imagine you have an electrochemical cell in its most basic terms. On the negative electrode you have 3 moles of iron metal in a chloride solution. On the positive side you have 3 moles FeCl3 solution. These are separated by a...
2. ### I Transfer of electrical energy and transfer of air energy

Is there a way to know what is the amount of energy a wire can transport and know what is the amount of energy transported by moving air at a certain psi.
3. ### I Does gravitational energy travel like electrical energy?

Electrons flowing through a resistor are dissipating electrical energy. The electrical energy is transported from the battery to the electrons along the curved field lines of the Poynting vector. It seems like a meaningful idea that electrical energy necessarily travels from the source to the...
4. ### Calculating Electric Potential and Energy in a System of Spherical Conductors

(a) Using Gauss's Law ##E_P=\frac{q_1+q_2+q_3}{4\pi\varepsilon_0(R_1+R_2+R_3+d)^2};(b) V_3-V_1=\int_{R_3}^{R_2}\frac{q_1+q_2}{4\pi\varepsilon_0 r^2}dr+\int_{R_2}^{R_1}\frac{q_1}{4\pi\varepsilon_0 r^2}dr=\frac{q_2}{4\pi\varepsilon_0}\left(\frac{1}{R_3}-\frac{1}{R_2}\right).## (c)...
5. ### Engineering Electrical energy to empty reservoir with a siphon water pipe

Calculation of the potential electrical energy generation of a siphon pipe, emptying an enclosed reservoir and end of siphon pipe connected to a pelton turbine with efficiency of 75% Known inputs: Height difference of siphon(Hd) = 4,5m Height lift of Siphon (Hu) = 6m Total siphon pipe length...
6. ### Electrical energy stored by charged concentric spherical shells

I thought up of this problem myself, so I do not have solutions. I would appreciate if you could correct my approach to solving this problem. Firstly, the charge induced on the inner surface of shell B is -q, and so the charge on the outer surface of shell B is Q+q. The energy stored can be...
7. ### Magnetic Permeability: Temperature Effects

One more thing i forgot to add, is magnetic permeability of a metal constant irrespective of its temperature including superconducting temperature ?
8. ### How does electron speed affect electric power?

I've got a quick question on the relationship between the kinetic energy of individual electrons and the total electrical energy they create. I have a radioisotope - a beta emitter - which produces electrons with around 1 MeV (1.60218×10-13 Joules / 4.45049×10-17 Watt-hours) of energy. I keep...
9. ### B Converting 10 PSI to Electrical Energy

This is not my subject, but I need to know if I can convert 10 PSI to energy. for example, If I have a permanent magnet motor rotate X time (RPM) to produce 10 PSI. Now Can I invert this process, if I have 10 PSI and let it pass on a permanent magnet motor, How much electricity will produce? in...
10. ### Electrical energy transmission is on the inside or outside of a conductor

Hi, Is it true that the transmission of energy is not inside an electrical conductor, but outside the metal. this even for frequencies around 50 hertz. Thank's
11. ### A single wire electrical energy transmission....

Single wire electrical energy transmission without a (ground ) return path... A new way of transmitting electrical energy from a floating totem pole node to almost 500 miles away end point of propagation... My totem pole electric charge supply is made of a high voltage battery and two switches...
12. ### Question about Electrical Energy

I know that energy cannot be created nor destroyed. However, I also know that voltage is basically electrical potential energy. So, how can a transformer exist? In terms of classical mechanics, in order to increase the PE of say, a ball, you must lift it (expending energy) higher above the...
13. ### Can I covert magnetic energy to electrical energy?

Hello Before I start, I would like to clarify that I know Perpetual Motion is not possible & Energy can neither be created nor destroyed, But Can be change from one form to another. That's exactly my point. If I could convert energy from one to another, then why couldn't I just harness energy...
14. ### Conservation of electrical energy on a conductor

I'm having trouble seeing how electric potential energy production on a conductor follows conservation of energy. Let's use the photoelectric effect as an example. A photon with energy E = hν strikes a conductor, ejecting a photoelectron with a maximum kinetic energy of hν - φ. Assuming the...
15. ### Why we say that electrical energy is power over time p x t

Greeting . how electrical energy can be power over time when electrical energy is actually potential energy . from a lot of sources (wiki ,study.com..) comes the information that electric energy is potential or kinetic energy in other sources is said to be electric power p x t so i am...
16. S

### What is the reason for harmonics in dc-dc converter?

There is a nonlinear switch in every dc-dc converter.Is it the reason of harmonics in output voltage?
17. T

### How does an electric motor convert electrical energy to mechanical energy?

how does electric motor convert electrical energy to mechanical energy. Hello I do not understand the following electric power is P = V * I electric motors operate on the principle of repulsion and attraction of magnetism. What confuses me where that power ends because as far as I know, the...
18. ### Kinetic energy to electrical energy generator

I am going back over the topic of electricity and energy. I am just wondering within a kinetic energy generator what is the relationship between the speed of the rotating shaft and the overall electrical output of the generator. Thanks
19. K

### Calculating the electrical energy of a buoyant force

Should be a simple question. Hopefully... Buoyant object rising in water pulls on a cord attached to a generator. How much power is generated? Object Volume = 100m2 Liquid is plain water = H2O Depth = 100m I understand that Archimedes Principle is the buoyant force = the weight of the...
20. ### Calculate Efficiency of Motor Lifting 0.050kg Block at 0.40m/s

Homework Statement A motor lifts a block of mass 0.050kg at a constant velocity of 0.40m s-1. The current in the motor ia 85mA and the potential difference across it is 3.0V. Calculate the efficiency of the motor Homework Equations Ek = 1/2 x mv2 Electrical power = VIt The Attempt at a...
21. ### Electrical Energy: 30-Day Output from Coal Plant

Homework Statement A power plant burns coal and generates an average of 700.0 Megawatts (MW) of electrical power while discharging 1162.00 MW as waste heat. Find the total electrical energy generated by the plant in a 30-day period. Homework Equations W = J/sec The Attempt at a Solution...
22. ### The Electrical energy of a conducting cylinder

1. The problem stsatemesnt, all variables and given/known data A cylinder conductor of length ##l##, inner radius ##a## and outer radius ##b## is half-filled with a liquid dielectric as shown in the picture. The cylinder is attached to a battery of constant voltage ##U## and then separated from...
23. ### Electrical potential energy question

Why does the potential energy of a system of two charged particles decrease as the distance between them increases? It seems that the PE should increase, as in U=mgh; as h increases, the PE increases. Why does this not occur in electrical potential energy, and in the gravitational potential...
24. ### Electrical energy converted to heat in coil

Homework Statement Given a coil with N turns, a radius of r, a resistance of R', and an induced current i'(t) running through the coil, determine the totale energy converted to heat in the coil for t>=0.EDIT: The circuit on figure 4 consists of a resistance R and a capacitor with capacitance...
25. ### Maximizing Heat Output from Electrical Energy: Heat Pumps vs Heaters

I have read that when we directly use 'W' Joules of electrical energy to heat a liquid,the maximum heat we can use to heat the liquid is W. However, when we use a heat pump Q=[COP+1]*W , and that means Q > W. Hence heat pump is more efficient and is preferred over electrical heater. Doesn't this...
26. ### Generate electrical energy from vibrating transformers

Hey guys, how are you? I just have an idea but can't figure it out how to solve it. Is it possible to generate electrical energy from a (high power) transformer vibration using piezoelectrics?
27. ### Conversion of friction energy in to electrical energy is possible?

It is possible to convert frictional energy into electrical energy directly?... please tell me and if possible give me the formulae...
28. ### What about converting sound energy to electrical energy?

is that possible pls help me!
29. ### Converting heat into electrical energy

Greetings, I have a science project to make and i have an idea but i am not so sure about it, the idea is to convert thermal energy into electrical energy which will run a small engine. I want to put that device in a cooking pan and that heat will be converted into electrical energy which will...
30. ### How to store electrical energy?

Hello I made a little wind turbine so when it is directed at wind it turns and generates electricity as I can see the outcoming voltage on voltmeter. My question is how can I store its energy? Can I use a rechargable battery and let it run out, then stick copper wires at each sides of it coming...
31. ### "Attraction Force x Energy Accumulation" clarification

First of all, I did not major in Physics, but I did pass GCE with A. (This is to make a point, not to boast.) But there's a matter that doesn't make any sense to me, and none of my acquaintances could give me the clarification so I came to this forum, hoping someone can make me understand this...
32. ### Electrical Energy and Coulombs Law

Homework Statement Charge q1 is fixed to a spring with constant k_s. It is at equilibrium initially and located r+x away from q2 (which is oppositely charged). The charge q1 is released and allowed to move closer to q2, pulling the spring and stopping. Now the charges are only r distance away...
33. ### Total rate at which electrical energy is dissipated by resistors

Homework Statement A resistor with R1 = 25.0Ω is connected to a battery that has negligible internal resistance and electrical energy is dissipated by R1 at a rate of 36.0W. If a second resistor R2 = 15.0Ω is connected in series with R1, what is the total rate at which electrical energy is...
34. ### Solar energy into electrical energy through CPVs

Homework Statement How much percent can CPVs (Concentrated Photovoltaic cells) convert solar energy into electrical energy? Homework EquationsThe Attempt at a Solution According to this page, "http://www.benefits-of-recycling.com/solarenergycars-2/ ", 20% of solar energy is converted into...
35. ### Find the electrical energy supplied in kJ and kWhr

Homework Statement a mass of 15kg of air in piston-cylinder assembly is heated from 25°C to 77°C by passing current through a resistance heater inside the cylinder. the pressure inside the cylinder held constant at 300kPa during the process and heat loss of 60kJ occurs. (Cv= 0.718 kJ/kgK)...
36. ### Direct conversion from heat to electrical energy

Hi to all. I'm looking for ways heat could be converted directly to electrical energy. I figured out some machinery out there that can convert heat to electricity by difference between temperatures, but this method seems to be inefficient. I just came with an initial idea of how a new machine...
37. ### How do radio antennas convert electrical energy into photon energy?

How do transmitters convert electrical signals into photon energy?
38. ### Conversion of Electrical Energy to Heat

I've done a school experiment converting electrical energy to heat. P=VI was used to find the electric power going through the Ohmic heating coil, and got an answer of 30 watts. It was used to heat 0.2kg of water and the equation Q/t = m×c×T/t was used to find the Heating Power which gave an...
39. ### Finding electrical energy used by a light

Homework Statement find electrical energy used by the light if the voltage on the battery is 110 V and the current in 2.0 minutes is 10 mA V = 110 I = 10 mA Homework Equations R = V/I The Attempt at a Solution 110 V /.010 A = 11,000 ohms = 11 k ohms I'm new to...
40. ### Electrical energy production question

Homework Statement If all the solid waste of 230 million tonnes were burned in waste-to-energy power plants that are 20% efficient, a) how many kilowatt-hours of electrical energy could be produced in a year? Compare this quantity with the total U.S. electrical energy production of...
41. ### Electrical Energy Dissipation Across Resistors

Homework Statement (image attached) A). What is the total rate at which electrical energy is dissipated in the 5.0−Ω resistor? B). What is the total rate at which electrical energy is dissipated in the 9.0−Ω resistor? C). What is the power output of the 16.0-V battery? D). At what rate...
42. ### How Much Electricity Can Be Generated from a Weighted Anchor Chain?

I am trying to calculate the output of a weight imposed on a electrical generator via a gearbox. Can anyone please help me with this? Let say the weight is 500 000 metric tonnes. How much electricity could this produce if putting a constant force on the gearbox? This is a theoretical...
43. ### Converting sound to electrical energy

Is there any possibility to converting sound energy to electrical energy by using piezo electric material.
44. ### The electrical energy produced from chemical reactions

Hi there, new member here (**TL,DR is available at the bottom of this post**) As you may or may not know, if you were to put in a plate of zinc at one end and a plate of copper at the other, put them in an acid solution, electricity will be produced. More of that stuff here...
45. ### How do I calculate electrical energy transferred?

Can anyone tell me how to calculate electrical energy transferred when you are given a voltage and a charge? I'm really stuck as we haven't covered this before :-/
46. ### Converting heat energy to electrical energy

I'm going to ask a very basic question and my attempt at solving it may not even be right. Electricity is basically flow of electrons in a conductor, so what I was wondering is if I start heating the wire the atoms will start losing the electrons and everything will be moving in a chaotic way...
47. ### Calculating electrical energy over time

Hello, Let's say I am generating 5 amp at a constant 1 volt and storing it in a battery without any loss of energy. The question is what am I adding to the battery? Am I adding power as a function of time or is it something else? So say if I were to calculate how much energy has accumulated...
48. ### Confused on the Electrical Energy Formula?

This is probably a silly question. The Electrical energy formula is this: Ee = k(q1)(q2)/r So let's say a positive and negative charge are directly next to each other. Conceptually, there should be no potential energy there. But the formula (r=0.00001m) suggests that it is huge. On...
49. ### Is all electrical energy eventually lost as heat in solid state electronics?

I've never heard it said before but it appears to me that all electrical current that flows in a solid state component system; processors, diodes, transistors, resistors, etc. is eventually dissipated as heat. What are your thoughts about this?
50. ### Electrical Energy Electron Question

Homework Statement Two electrons are fired at 3.5x10^6 m/s directly at each other a) calculate the smallest possible distance between the 2 electrons me=9.1x10^-31 Ve1=3.5x10^6 m/s qe=1.6x10^-19 C Homework Equations Em1=Em2 The Attempt at a Solution Tried using Em1=Em2...