Power Definition and 998 Threads

I'm looking for advice on how much power is required to compress air in a gas turbine engine - parameterised by degree of compression and mass flow. Normal gas turbine engines have exhaust turbine(s) on the same shaft as the air compressors. They bleed some of the exhaust energy to drive the...

Hi I'm reading through a Quantum Mechanics textbook called Quantum Mechanics by Book by Alastair I. M. Rae and in the opening chapter it talks about the Heisenberg uncertainty principle and talks about how a measurement of position of a particle causes an uncertainty from the momentum due to the...

What is the difference between water power and turbine power? Do they have the same formula?

Hello What are benefits of nuclear power plant electricity than hydro power generated electricity Does it cost less per unit any or the waveform is pure sine wave how engineer build it .

How can the slightly richer Air fuel ratio produce higher power while the temperature it produces is lesser than slightly leaner(slightly leaner than stoichiometric for best economy)? FYI:I understood that ,at the stoichiometric ratio(precisely slightly leaner due to fast operation of engine)...

Does anybody here have experience with whole house power conditioners? We live in an old neighborhood with old overhead powerlines, and it's been a rough fall for brownouts and other little transient "interruptions". I already have UPS's on delicate stuff (basement server, PC, home theater), but...

In the Zermelo-Fraenkel axioms of axiomatic set theory we find: Axiom. Given any set x, there is a set such that, given any set z, this set z is a member of if and only if every element of z is also an element of x. Why is this needed as an axiom? why isn't it merely a definition? Under...

I'm starting to get into RF electronics, and an upcoming project involves the use of a power meter / SWR meter. How do we model a power meter in terms of an equivalent circuit? i.e. is it just another impedance? or a transformer? or does it not effect the circuit at all, so we just don't include...

Before I begin I have to note that my last thread of this kind got heavily moderated and closed because the moderators did not like the specific way in which I was formulating my questions, so now I want to clarify and reaffirm some of what I have learned through questions without making any...

Homework Statement Shown in the figure Homework Equations W= (p2v2-p1v1) / (1-n) The Attempt at a Solution I am not sure where to start and where to use all the data given in the table. Please help. It would be nice if someone could explain the basic nature of the steam turbine, how it...

Hello, I'm trying to solve a question, please help me.

Homework Statement Hello to everyone who's reading. :) I hope I posted this in the right place; while this is not exactly a homework problem, I am trying to improve my understanding of the background information before proceeding with course-style problems. This post is because I'm trying to...

Hi all I am in search of a Power Amplifier (preferably Solid state pulsed amplifier ) which is able to output around 340 Vrms across 25 ohm impedance load (acoustic transducer operating at approx 4.5 KW) in pulsed mode with duty cycle less than 1%, maximum pulse length of 5 ms and operating...

I have looked over the types of generators used in most power plants (Hydro, Nuclear, coal etc) and with different sized and rotor rpm's they all basically share the same principle of operation if I'm not mistaken, which is that the rotor gets supplied via brushes and slip rings with a DC...

Hi all I have been looking at understanding power for a simple energy generation concept, and I think that I originally made an error in my calculations because I wasn't considering the relative velocities. So I basically generated the force made by a kite in static conditions, but if I need to...

I am working on a solar trough power plant to power my farm and greenhouses.

Interesting article sent out by Digikey just now...

I am trying to get relay to come on when it gets dark outside this works with one LED and 600 ohm resistor but it does not seem to turn on relay I get 20 ma draw when applying 12 volts to coil it seems you need transistor or SCR to to turn on relay. Relay I think was from a TV it's only 1/2" X...

Homework Statement Problem in Fig 2-18 and its solution: Homework Equations Passive Sign Convention, I think. The Attempt at a Solution Let's say i is counter-clockwise. Then, it's going from - to + of v_b. Why is there not an additional negative sign in computing p_b, and why is there one...

Hello. In fields and waves and transmission lines We have a attenuation constant formula with power relations: 1- Alpha = 1/2R0(R+G|Z0|^2) 2-Also we can calculate attenuation constant from these : Z0= radical[(R+jwL) / (G+jwc)] gamma = radical[(R+jwL)(G+jwc)] I want show alpha from 1...

Is there some common parameter for DC power supplies that provides the maximum oscillation amplitude allowable at the output? For some context - I would like to generate an oscillating signal powered by a DC power supply, but to prevent most of the oscillations reaching the DC supply I am going...

The average loss of energy in a material per unit length of a particle (in particular an electron, which is stable) is described by the quantity ##dE/dx##. - for ionization it is given by the Bethe-Bloch formula $$-\left\langle {\frac {dE}{dx}}\right\rangle ={\frac {4\pi }{m_{e}c^{2}}}\cdot...

Homework Statement Weight - 200kg RPM - 5 Diameter - 6m Homework Equations Moment of Inertia I = (weight/9.8).r^2 Torque t = I * (angular velocity / t) Power = Torque * speed The Attempt at a Solution First I calculate Moment of Inertia Using I=(weight/9.8) * r^2 = 183 kg. m^2 Then I...

Hi, I have a Dell Inspiron core i5 PC. It beeps in sequences of 4 bbebeeps at a time shortly after power goes on , won't boot up nor complete Post . It may have to see with ram problem I have been told. Is this correct? Ultimately, what can I do?

I have a 30V 5A variable linear power supply, which has failed twice from transients killing the LM358 quad op-amp IC that controls the output. These transients are from driving things like a car ignition coil, for making an electric fence energiser. Simply replacing the LM358 gets it going...

I have a question with regard to split single phase (in United States) electricity. I understand that there are 2 hot legs each 180 degrees out of phase at +120v and -120v (240v between hot legs) going from transformer to breaker box and a center tapped neutral Earth bonded wire at 0v with...

I'm in year 11, doing Physics for GCSE and my actual ending GCSE is on Friday which Is where I finish school. I'm 16 and in the UK, I need help with the following equations: P = I^2 x R (why is this equation used) - all the power equations - How to calculate uncertainty << Mentor Note -- OP...

As common I mean inductances and eq resistances. I've been searching for high voltage transformers (to use with a 12-pulse rectifier) but I only see catalogues just trying to sell the thing. Do you have any recommendation as a book or another reference?. Thanks in advance!

I have a dBW value and dBW I understand to normally be given as representing a RMS Power (however this is not specificically ever stated and I am told its just assumed?) from dBW to Watts = 10^(dBW/10) This then gives RMS power in Watts At what point do I convert this from a RMS to a peak...

I had an idea of building an FM receiver that is powered from the electromagnetic fields generated by power-lines. My question is , how can I make the electromagnetic field receiving antenna? Will a simple copper coil work? If so, can the same coil be used as the RF antenna or will that have to...

I am trying to create a lever which has mass on one end and i need to lift the lever. A picture showing the lever setup is in this link: https://imgur.com/WeH4oK7 The system is like seesaw ( from -20 degrees to +20 degrees at constant angular velocity for time period 't') The input angular...

Homework Statement Hello, I suspect this is an easy answer but I am not seeing it. I am reviewing (more so for fun / hobby) some differential equations – I’m not in school. I’m needing help with an example problem in Differential Equations With Boundary-Value Problems Zill 2nd edition. In...

How can I calculate the loss of potential energy when forces are applied but no motion in the system occurs? Here's an example: Let's say I build a battery operated car that is set to drive forward, but I put it right in front of a wall. It attempts to drive forward, but instead it just pushes...

I have seen that typically most 110Kv and 330Kv lines around my place have not 4 wires on them (3 phases and one neutral) but rather 7 wires on them, which I suppose is 3 phases x2 which probably means two cables for each phase and a common neutral wire at the top of each post. Now is my...

Homework Statement Determine the resistance of a 30 km long wire. b. Assume that the line transfers 1000 MW of power at a potential difference of 500 kV. What is the current through the wires? c. How much power is lost during transmission? What fraction of the transmitted power is lost...

Help me please:) (1) An idealized engine with constant torque curve means constant acceleration. So for example if there is no air resistance and no frictions and car is on fixed gear and at 3000Rpm it produces 50Hp so at 6000Rpm will produce 100Hp. So he doubles the speed , doubles power and...

So apparently the proof involves a trick that converts the problem of a general power set ##\mathscr{P}(M)## of some set ##M## which has of course the property of not having pairwise disjoint set-elements to a problem that involves disjoint set-elements. I do not understand why this trick is...

I am searching for a legible schematic diagram for a Tenma 705-72 DC laboratory power supply. Each of its two channels uses a LM723 regulator and a pair of 2N3055 power transistors. One of the channels operates normally; the second channel puts out the maximum voltage (37 volts). Any help...

Why does a turbine in an energy plant experience more resistance if the electrical load on the other end increases (electrical resistance decreases)? What I don't understand is how the force that drives for instance a washing machine gets through the power lines that don't seem to experience...

I would like to know if there is an official name for the class of integers that are (not) perfect powers. A perfect power is a number that can be expressed as xn, where x and n are both integers > 1. I have been calling these integers "roots" - since they do not have any integer roots of their...

I know the CMOS battery keeps the time and BIOS settings , but what is powered by the batter to keep time? A crystal oscillator? And why is it so crucial to keep time on a regular desktop computer?

Homework Statement It is desired to magnify reading material by a factor of 3.5× when a book is placed 9.5 cm behind a lens. What is the power of the lens in diopters? Homework Equations 1/f = 1/di + 1/do M = -di/do P=1/f The Attempt at a Solution I set equal the magnification to -di/do and...

Hi PF Is it possible to perform accelerated lifetime test of thermal ageing on power cables? Let's assume that the cable manufacturer guarantees a service life time of 20 years at max operation temperature 90 [degC]. Is it possible to estimate the expected life time of a cable if I choose to...

Homework Statement The problem is attached as pic Homework Equations ∑(ƒ^(n)(a)(x-a)^n)n! (This is the taylor series formula about point x = 3)The Attempt at a Solution So I realized that we should be looking at either the 30th,31st term of the series to determine the coefficient. After we...

Hey everybody, Its recurrent in Power System Analysis and Electrical Instalations the SL diagram. I need recommendations of books in which I can read about it. I've done a little research but couldn't find anything. Thats amusing, in which classes are this diagram teached for the first time...

Hello pleas i need help how to calculate needed power(of engine) for blending granual material in machine. Machine looks like on pic below thank you

Homework Statement Give two reasons why transformers are an important part of the power distribution grid My lessons don't have any information regarding this topic. I have read everything in my lesson and can't find anything to answer this question. please help. thank you

Hello Please give me some advice on a lot my wife and 2 kids are thinking on building our home on in SC. It will be located next to a large power line right of way. Its near a lake so we have those big metal towers. I'd say the nearest tower from my house will be like 50 to 75 yards. I took a...

Homework Statement in title Homework EquationsThe Attempt at a Solution so i know that i have to use the ratio test but i just got completely stuck ((2x)n+1/(n+1)) / ((2x)n) / n ) ((2x)n+1 * n) / ((2x)n) * ( n+1) ) ((2x)n*(n)) / ((2x)1) * (n+1) ) now i take the limit at inf? i am stuck here i...

Homework Statement Im going over some revision for fibre optics and I've come across an example question to calculate the power margin of the system with the following info is given: transmitter power = -10dBm Connector loss = 1.5dB Attenuation = 3dB/Km Total length= 2KM Receiver threshold =...