Power consumption Definition and 55 Threads

Here is the circuit. Note that no current flows between the left and right sides of the circuit: their only relationship happens through the MOSFET that is parallel to B. There are eight cases to consider: all the combinations of ON/OFF for the three MOSFETs. Here is a summary of the eight...

I want to heat 10kg of water from 20C to 80C-90C with the lowest power consumption. One option I consider is to use an electric heater and the other option is to use a heat pump. Are heat pumps common for such an application? The calculated power consumption of the electric heater is 0.7...

I've been reading this thread about power consumption of a domestic fan and @SentinelAeon says he's using a kill-a-watt meter. The accuracy for power measured to an induction motor will depend very much on the way the meter works. A Google search only turned up sales and 'user' pages. Does...

Hi I was wondering about the astable multivibrator . Does the circuit consume power while the diode if off ? If yes how much ? Please explain in detail. Thanks

I have occasion to attempt to alleviate a lot of confusion on behalf of my utility (and me). Despite a well-trained search engine I can't seem to find a white paper from another utility/IEC/IEEE that tackles this question. Does anyone here have a good source?

Hi. Not homework. I left that behind me 40yrs ago:) How much power (if any) does a plugged in but unconnected wall wart (transformer/rectifier) consume? Eg. I have a phone charger labelled as: Input: 100-240V~50/60Hz 0.3A. ____________ Output: 5V - - - -...

Hello, If I am trying to calculate the heat removed from a chiller system through this formula on engineering toolbox.com: Does COP or efficiency of the equipment come into play with this calculation? For example if a chiller is fully loaded isn't it running more efficient for a watt/ton...

Hi folks, My question relays on the difference of consumption power of a coil when it's on AC and CC regime. A coild is made of copper wire with air core, aplied on it a CC current of 1 amp, a measure was taked and nottice a 5W of power consumption. Then the power supply is changed to and AC...

Homework Statement (Is the image read-able now? ) The fig 1 shows the relationship between voltage and current when voltage is applied to a certain light bulb. Next, in fig 2, the bulb is connected in series with a 12-V battery and a 5 ohm resistor. Question : what is the amount of power...

A 2 stage compressor has a final delivery/discharge pressure of 250 bar. hydrogen is been compressed and stored in vessels. The pressure in the storage vessel reaches the delivery pressure(i.e.250 bar) and the compressor is still running ( vessel has a safety pressure of 450 bar) and the...

hi, i have a study on a plucker machine and it came out that when the rotational speed of the plate is low, the power consumption rate is high and if the rotational speed is high, the pcr is low. what is the possible explanation for that? thanks in advace.

Helly everyone. I'm new in physics and I don't understand many things there. What interests me the most is energy generation. I was mostly reading Wiki articles, and I found something I couldn't understand, so I'm asking for help. According to wiki, peak power output of the largest nuke ever was...

Being a man who learned physics in college, I have tried to calculate that in the simplest way. As for example, if we need to know the power consumption to compress steam from 50C saturated pressure level to 1 bar i.e. 100C saturated pressure level, the best way is to know the gross enthalpy of...

Homework Statement Note - I've asked a very similar problem to this before but I'm redoing it for practice, and this one asks a new question which just ruins everything. I also don't know if I was right the first time yet because I haven't gotten the paper back. Consider a refrigerator whose...

Homework Statement Consider a refrigerator whose 40-W light bulb remains on continuously as a result of a malfunctioning of the switch inside the refrigerator. The refrigerator has a coefficient of performance (COP) of 1.3 and the cost of electricity is estimated to be 10 cents per kWh...

Homework Statement Question 1: An insulated 8-m3 rigid tank contains air at 600 kPa and 400 K. A valve connected to the tank is now opened and air is allowed to escape until the pressure inside the tank drops to 200 kPa. The air temperature is maintained constant by an electric heater during...

Hello, I just came across this site when looking for some info. Not sure if this is a stupid question but I would like to know what the correlation between AC and DC power is when comparing one device. For example if i had a a device connected to 120vac and it drew 500w then the amps would be...

If we have a variable frequency AC supply in LCR circuit and when the frequency equals natural frequency the impedence is equal to resistance and the power consumption is purely that of resistive load circuit. Is this true even for other frequencies i.e. do reactance participates in power...

Homework Statement [/B] 2-3-15 Homework Equations [/B] P = power. W = work. U = internal energy. S = entropy. t = time. Q = heat. T = temperature. F = force. d = distance. P = ΔW/Δt= ΔU/Δt ΔS = ΔQ/T dm/dt = ρ⋅dV/dt W = F ⋅ d ΔU = Q - W Where m is mass, V is volume, and ρ is the...

Homework Statement Hello Everybody, When i was searching for power required to lift an object, i found that:- For Example, Q :- 100 kgs to be lifted 3 metres in 5 seconds. (vertical) A :- Mass * Gravity * (Distance / Time) = 100 * 9.8 * (3/5)...

My kids have some question to ask so bear in mind that they are in grade school. Hi, We have been talking and learning about motion and studying examples to understand concepts. One discussion was about what happens when you take a fan and blow it into another fan. The first fan would cause...

Hi Guys, I just want to ask if there is a relation between fan RPM and the fan power consumption. Because in some specifications I see, Power consumption is not consistently increasing as you increase the Fan RPM. If we lower the RPM , will we still achieve the same airflow? if we always set at...

I am talking about electromagnetism.. Can we construct a system with no power consumption.. I ve an idea... 1 we can construct rail route surrounded by dome shaped copper (actually cu strips to avoid eddy current) 2 rail on which permanent magnet is fixed will allowed to move on this...

Hi guys, For a science experiment I've got to measure the power consumption of my circuit of a 100W incandescent light bulb connected to the mains AC, with a dimmer switch to vary its brightness. I was planning on just using one of those plug-in energy monitors with a digital display but...

Homework Statement Determine the power consumed by a pump when it is pumping a fluid of density 1,200kg/m^-3 60m3/h at 500kPa with an 80% overall efficiency. Homework Equations I believe it to be: P = q_m ρ g h_p The Attempt at a Solution Stuck at the above part, I don't have enough info?

I need help in solving this, I am stuck half way. Please check if what I am doing is right and tell me what to do next. By the way, this work should be done without using the calculator, so let values such as √2 as they are. And values like sin(2t + θ) should be just left like that, too...

I need rough values for power consumption of an average sized car at different speeds. Does anyone know how to either calculate or where I could find such information? Thanks

Homework Statement If a 70kg man is running 3 m/s horizontally, how many watts is he consuming? Homework Equations W = N-m/s N = mass*acceleration The Attempt at a Solution I would assume that in order to get the force in N one would use the gravitational constant of the Earth, but...

Homework Statement A toaster with 18Ω is conducted to a 220 volt source. What is the power consumed by the toaster. Homework Equations P=IV The Attempt at a Solution P=18(220) P= 3,960

Homework Statement What is the power consumed when plugging an iron with a rating of 10 amps to a 120 volt outlet? Homework Equations (watts/volts)=amps The Attempt at a Solution (w/120)=10 amps 120= 10 amps (w) 120/10=12 12 watts.

Hi all, Mechanical engineer needing some electrical help. So electrically piezo actuators are modeled as capacitors. Power(P) = C*U*dU/dt, where U equals voltage. I'm seeing several sites like here: http://www.piezo.ws/piezoelectric_actuator_tutorial/Piezo_Design_part3.php They...

In short, if I want a given frequency, and I use BJT transistors, what would be the optimum capacitors and resistors in a multivibrator. Example: http://upload.wikimedia.org/wikipedi...tivibrator.svg So, what are the optimum values C1=C2, R1=R4, and R2=R3?

I'm just looking over some introductory notes to transistors and it says that BJT transistors are useful for amplifying current, so does this mean that power consumption (P = VI) in a circuit would be reduced because of a smaller input current? Or is the power consumption calculated by the...

Homework Statement Okay, all I want to know is, what are the equations/information I need to solve this question. I'm not too sure. Homework Equations Not sure The Attempt at a Solution

Hi, I am trying to model a phones increased performance due to the integration of a DTC network. I have the spec sheet on the part but for the live of me cannot interpret it to generate the information I need. I need to find the Power in and out of the component to determine gain and...

Hi everybody, I'm building a board game right now. The game consists of a train of gears that I would like to drive with an electric motor. The gear train can be many different sizes (# of gears) and patterns (size of gears). What I would like to do with the motor is measure the...

Let's say you have two batteries in parallel and at the same voltage. Well batteries fluctuate in voltage and when they are drained they will have a somewhat lower voltage than what they started with when fully charged. Because of this, when power (or current rather) is being drawn from a...

Hello all, I am a first year college student who has just been through Calc I, and I am working to put some concepts together. I am also new to the forum. I am working out a thought experiment, and I have what I believe is a correct solution. I would appreciate it if someone could verify...

Would buying a laptop save me a lot more money on my electricity bill than a desktop?

Why does TTL consume more power than CMOS? I googled but did not find any useful information. I can think of the Base emitter diode drop as one cause. But are there other reasons why TTL consumes more power. Can I compare the ON resistance of MOSFETs Vs BJTs?

Hi there, i have a specific question concerning power consumption in a rotating system and hope that somebody out there can help me out. Lets say we have a wheel, powered by an e-motor, that is surrounded by magnets that are attached to the edge of the wheel ( like a cog wheel but magnets...

I'm studying the ethernet devices and the transmission system over cable wire and I'm interested especially on the power consumpiot due to the binary transitions from 0 to 1 and viceversa in the transistors. It is possible to estimate how many WATTS (i thinks nW) are necessary to the device to...

Just a hypothetical question here. It's just a thought that popped into my head that I thought was an interesting topic. Seeing as many companies now have data centers and server farms, what would to say consumes more power overall? All of the technologically superior countries' companies'...

Homework Statement Given circuit consists of two resistors ( R1 = 330 Ohm , R2 = 22K Ohm ) , an LED ( Forward voltage = 1.6V, forward current = 20 mA) , a BC 337 NPN transistor and a 9V battery supply. I need to find the total power consumed by the circuit for a run time of continuous 1...

I just bought a Coolermaster HAF 932 full tower PC case for my gaming rig. It has about Five or Six, large case fans in it. I also bought a Coolermaster V8 CPU air cooler. It say's on the box of the V8, that the cooler itself can consume a maximum of 180 watts of electricity. I find it utterly...

Homework Statement If the average KWH used per month in a household is 1650KWH for the year, what is the average power consumption rate in watts that gives this average KWH energy value? Homework Equations KWH X 1000WH/1KWH = W? The Attempt at a Solution 1650KWH x 1000WH/1kWH =...

Homework Statement (a)A 60 W, 115 V lightbulb has a resistance of 10.9 W when cold (20.0°C) and 132 W when on (hot). Calculate its power consumption at the instant it is turned on. (b)Calculate its power consumption after a few moments when it is hot Homework Equations P=V^2/R...

Homework Statement (a) If you follow a diet of 2140 food calories per day (2140 kilocalories), what is your average power consumption in watts? (A food or "large" calorie is a unit of energy equal to 4.2*10^3 J; a regular or "small" calorie is equal to 4.2 J.) Note for comparison that the...

can anyone tell me my quote is feasible? Electronic devices requires 1 to 12v approx to function. Indian Electricity board supplies us 230v for domestic & official appliances; so additionally we need an AC adapter to convert into DC (a sort of stepping down the power) . we cannot ask...

I'm trying to optimize pulse coils and determine power consumption. According to Ohm's law: P = V2/R where P=power / V=voltage / R=resistance Why isn't Ohm's law providing the same results as actual meter testing?? Testing coils with 1 "C" battery: 1.5 volts #1) 2.3 ohm coil...