Voltage Definition and 1000 Threads

Homework Statement Homework EquationsThe Attempt at a Solution Output voltage and output current of an OP-Amp Taking the OP-Amp as an ideal OP-Amp, the voltage at terminal 1 is 0 with respect to ground. The voltage at B is ## V_B = - 0.5 V ## ## i_{in} ## is from A to B. There is...

How is voltage equivalent of temperature(Vt=KT/q) defined and derived? Is it related to kinetic energy(which is equal to 3kT/2)?

I have a 5.5v .22F capacitor and I plan on using a 6v led on it for a project. Since I am not going to need to use it much and I am willing to do minor damage to the capacitor could I do that. By the way its for a school project so I will likely use it once or twice then keep it but never use it...

It's written in my book that if you have two points having the same voltage then you'll cancel the resistance between them ... how can I know if the voltages of the two points are equal ...( The resistances are given in the circuit .)

Hello! I've been working on a few soil based MFCs and I have been monitoring my voltage and energy output for a week now. I've made the electrodes by covering stainless steel metal meshes with activated carbon using epoxy. I've gotten some funky results as attached. As you can see... the...

Ok, so I am am trying to make a homemade capacitor that is 4700pf and 15kv. polyester at 125 micrometers thick can withstand 15kv so were good. here is the equation i used C=ε0 K A / D Where C = capacitance, ε0 is epsilons constant, K = dielectric constant, A = area of aluminum foil, and D is...

Homework Statement There is a conductor with the square-shaped area. the Radii are r1 , r2 with width b and resistivity ## \rho_R##. Find the resistance R between A and B 2. Homework Equations ##I = \iint_A\vec J \cdot d \vec A## ## \vec J = \kappa \vec E ## ## \vec E = \rho \vec J## ## V =...

Homework Statement the capacitance of each capacitors and the cell voltage Homework EquationsThe Attempt at a Solution I got the total capacitance = 8028/5333 uF total voltage = 36v total charge=289008/5333 uC

Homework Statement Homework EquationsThe Attempt at a Solution I can't seem to figure out the answer. Apparently, the right method involves saying that Vs is actually equal to the voltage Vgs + voltage across R1. I don't understand how Vs could be voltage across R1? This is what I have so...

This is a problem from my midterm that I'm trying to understand before my final. The question is; A voltage phasor is given by V = 12∠70° and the frequency is 60 Hz. What is the time-domain voltage at t = 1 ms? a. 1.47 V b. 5.11 V c. -0.335 V d. -4.73 V As far as i know, the only equation...

Homework Statement hello, just came across this type of question for first time. A voltmeter with a range of 0-30volts is to be used to measure a 120 volt circuit. calculate the value of the resistor to be placed in series with the meter. the sensitivity of the meter is 1000 ohms per volt ...

Hello How do I calculate the induced voltage in a passive signal cable that runs parallel to a 1 phase power cable? Cable A is the power cable I = 500 A Cable B passive signal cable where: D= 209.65 mm: distance between wires ( center wire to center wire) r= 10 mm: radios of each wire f=60...

Given two sets of load resistances and output voltages: Rload = 108 ohms - Vout = 9.6V Rload = 10 Ohms - Vout = 2.3V Find the source voltage and the output voltage when R1 and R2 are equal. When the resistance is very large, the voltage seems to be around 9.6. My assumption was that then the...

Hey everyone, I'm hoping that you guys will be able to help me with some calculations. I was on YouTube and came across this: I then began to wonder if I could make a solenoid using bitter disk as in the video, granted no where near as powerful. I would say 1 tesla using an iron core. After...

Homework Statement Two parallel plates located at a distance "L" from each other they maintain a potential difference "V" because of a battery (as shown in the picture). Through a small hole, made in bottom plate, electrons get into system (with mass "m" and charge "-e"), with velocity "v" and...

Hello, I was thinking that using AC to supply power to a lamp would cause it to flicker, considering that the potential difference keeps changing signs. This would mean that the current supplies voltage to the lamp, only to take it back after a really small amount of time. Voltage say's...

Dear all, I'm doing an RF energy harvesting circuit in UHF band. My question is about the voltage multiplier. My 2-stage multiplier (using 2 HSMS-285C diodes) follows Karthaus-Fischer's voltage-doubler. A 0.1F supercapacitor is put right at the output of the multiplier. This DC voltage will...

Homework Statement Homework Equations I am not sure exactly what this question is asking for, especially in regards to the voltage drop. How would the graph of voltage drop vs Rmax-Rmin be any different to what is already provided? The Attempt at a Solution

The voltage value on a wire a distance away from the signal-port (where we apply the initial voltage) has a phase delay because the current takes time to travel down the wire. But how do you visualize this? First we have a voltage at the beginning, and that causes current to flow. Then a...

Does an increase in Capacitance mean a decrease in voltage? Thanks!

I'm working on a small crank-able light using a DC motor,capacitors, and LEDs with a joule thief to drain the capacitors completely when the voltage in them drops too low for the LEDs. However I want the power from the capacitors to be able to go directly to the LEDs before the capacitors drop...

Homework Statement This is an example problem I found on khan academy and it didn't have an official problem statement... So I am going to have to make up my own problem statement from what was given. I can link the video if any of you want to see it. A positive charge 4uC and a negative...

Hello all, I am a senior electrical engineering student at Purdue University and I am working on my senior capstone project. One of the aspects of my project is to measure voltage and current waveforms as well as the relative phase shift between them. I need to get these waveforms into a data...

Hey, Theory: The voltage of a thundercloud is too low to ionize air particles and to produce a thunder. Particles of cosmic radiation are the trigger. I calculated whether the voltage of a thundercloud is enough to ionize air particles but the voltage was always to low. So I wanted to know...

i've built a bridge rectifier with a Zener Voltage regulator. 12V peak secondary 3300uF Capacitor 1k ohm load 1k ohm series resistor for the zener and a 1n4728A Zener diode. i'm getting a 2.8V steady voltage, but when i measured the current going through the load with my DMM it's measuring...

Homework Statement 1. For the first measurement, a load resistance Rload = 119Ohms results in an output voltage V(OUT) = 11Volts. For the second measurement, Rload = 11Ohms results in an output voltage V(OUT) = 3.2Volts. From these two measurements, determine the output voltage V(OUT) when...

Homework Statement Select the correct expression for ##i_o(t)## for ##t≥0^+##. Homework Equations ##V(t) = V(∞)+[v(0)-v(∞)]e^{\frac{-(t-t_0}{\tau}}## ##i(t) = C\frac{dV(t)}{dt}## ##\tau = RC## The Attempt at a Solution I'm a bit stuck on this problem. Specifically, I'm not sure how to deal...

I think I must have missed something when going over inductors for my electric circuits class. The voltage across an inductor is described by the equation: ##V(t) = L\frac{di(t)}{dt}## For the case where current is flowing through the inductor until ##t=0##, at which point the voltage/current...

Homework Statement Im doing a project on Emf and internal resistance. I'm just trying to understand what the load would be and where I would put the positive and negative pens on the schematic to find the load. Homework Equations Terminal Voltage would be what I have in the image above...

Homework Statement Then solve these equations for i1-4 Homework Equations V=IR The Attempt at a Solution 80i_1-50i_2-30i_3 = -120 -50i_1+100i_2-10i_3-25i_4 = 0. -30i_1-10i_2+65i_3-20i_4 = 0. -25i_2-20i_3+100i_4 = 0. i_1=-4.18239492 i_2=-2.66455194 i_3=-2.71213323 i_4=-1.20856463...

Homework Statement 1. In Figure A-1 of Experiment 18, assume that Vdc = 8Volts, R1 = 1kOhms, R3 = 7kOhms and there is no R2 resistor. Determine the current in R1 when the transistor is fully on and carrying current. Express your answer in mA. 2. In the circuit of Figure A-1, Experiment 18...

Homework Statement I want to know the voltage between a and b in the drawing below.[/B] Homework Equations V= IR The Attempt at a Solution The resistors 5Ω and 5Ω are in series: (Req)1= 5+5=10Ω The resistors (Req)1, 5Ω and 10Ω are in parallel: 1/(Req)2= 1/10+1/5+1/10=2/5 (Req)2=2.5Ω The...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] in the solution sheet, He took the 18 ohms parallel with the 9 ohms and not the 6 ohms. I don't understand why he took this approach. I was going to take 18 ohms parallel with the 6 ohms...

Homework Statement 1. A sinusoidal source with RMS voltage V = 11Volts across a resistor R = 50Ohms, determine the dBm value. Hint: you will first have to determine the power delivered and then check the formula for dBm calculations. 2. A type of coaxial cable has a loss of 12dB/100m at some...

Homework Statement Not technically a homework question but part of a piece of work I am studying. I need to calculate the voltage at the node in between the 10k and 27k resistors in the following schematic. I'll call it Vo. https://www.physicsforums.com/attachments/213624 Homework Equations...

Question: The question and the solution are attached below. It asks to calculate the voltage and in the answers and the bottom, it says the voltage is 890mV. What are the values used to calculate this number? It tells me the equation V = sqrt (VR) but I don't know the values to to put into...

Well let me explain. I've finished a circuit that consists in a microcontroller unit (in this case a PIC16F877A) that is connected to a LCD module, a keyboard and a RTC module (via I2C protocol). As far as I know all of them require VCC (=+5V) for operating so I needed to create a +5V regulated...

Homework Statement Two sinusoidal voltages with amplitude 15Volts and frequency 2,771Hz are separated in time by 68% of a period. What is the phase shift in degrees between the two signals?Homework Equations y= Asin(omega)(x-h) The Attempt at a Solution I know my A is 15 and I'm pretty sure...

So this is an example given to me in one of the guides. I am somewhat confused as to why R and R1 are considered parallel when the switch is closed at t=0. I thought that the two resistors cannot be parallel since there is a voltage source between them. One hypothesis I had was to treat it...

Homework Statement Find the voltage across the capacitor given the data underneath the circuit. Homework Equations Voltage Divider Rule Thevenin Equivalent Ohms Law The Attempt at a Solution I have tried using the Voltage divider rule but I can't seem to get the right answer. The correct...

Homework Statement The current source and voltage source in the circuit shown in the Figure below are connected in parallel so that they both have the same voltage, vs. The current source and voltage source are also connected in series so that they both have the same current, is. Suppose that...

Homework Statement 1. The characteristic decay constant for a capacitor C discharging through a resistor R is the product of R times C. If the initial voltage at time t = 0 is Vo = 13Volts and what is the voltage at time t = 2RC? 2. A capacitor C = 9microFarads is charged from 0Volts to...

In my physics textbook it says that ammeter in circuit C shows higher current than ammeter in circuit A and D. And the voltmeter shows higher voltage in D than in B, and C. It's explained in the book that way: some electric current is passing through the voltmeter in C, thus the ammeter will...

If I have a resistor and a voltage source in series but then I apply a short circuit in parallel to both of them would the voltage source and resistor not receive 0 V? Thus having 0 current. What would change in the circuit?

Homework Statement I have problem at output of the first opamp . About 3 -4 minutes , the opamp's output voltage decreases by 0.1V . Although I reduced gain of opamp to 2, but the opamp 's output was still reducing 0.1V about 3 -4 minutes . Homework EquationsThe Attempt at a Solution

Hi, I am trying to figure out the peak voltage across a capacitor when charged by 1/2 wave rectified AC. The formula for instantaneous voltage is : Vc=Vs(1-e-t/RC) where: Vc=Capacitor voltage, Vs=Source Voltage, t=time RC = the capacitor time constant So I thought I could integrate with...

Homework Statement I am practicing diode circuit analysis for an ideal diode model and constant voltage drop model.I have an initial circuit shown here: Which I then redraw to look like this: I want to make sure my process in redrawing this was correct. When I attempt to get current through...

Hi. As far as I know, the main reason for using AC in electric power transmission is that voltage can easily be transformed. If there was a similarly easy way for transforming DC, would power grids work basically the same? To be more specific, how much does AC power transmission rely on the...

Whether the increased voltage accelerates the electrons since the current of one ampere is one coulomb of charge going past a given point per second, it seems to me somehow the most logical. but I'm interested in the opinion of others on that topic.

Homework Statement [/B] 1. Using the Schematic of a 555 in astable mode from the Wikipedia entry on '555 Timer IC," resistor R1 = 8 kOhms and capacitor C = 3 micro-Farads. Determine the value of R2 so that the output duty cycle is D = 0.7. Note that D is not expressed as a percentage here for...