Voltage Definition and 1000 Threads

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...

[SIZE=16px][FONT=Helvetica Neue]Spec [SIZE=16px][FONT=Helvetica Neue]My job, as an undergraduate EE student, is to create a test rig for offsite electronics (environmental sensors hooked up to a data logger, 12V batteries and solar panels). The test rig should be able to evaluate output from...

Homework Statement The input signal of the circuit shown below is ##x(t)=2\sin (ω_ot + \pi/6)##. The switch in the circuit is controlled with a digital signal of the form ##s(t)=\sum_{k=-\infty}^{+\infty} (u(t+ε-kT_s) - u(t-ε-kT_s))##, ##\frac{2\pi}{T_s}=800\pi##, ##ε\to 0##, so that when the...

Hi, I would like to implement voltage regulator based on microcontroller + triac. I am able to calculate source RMS voltage by sampling signal using ADC, but don't know how to calculate triac angle to set desired RMS voltage. For example i have 250v source RMS voltage and i need to calculate...

If voltage is the difference in charge between 2 points, then why for a capacitor of a larger area or thinner dielectric cross section, do they say that it can store more charge given the same apppied voltage? Isnt voltage the difference in charge between 2 points? So if you can store more...

I have this piece of instrumentation that I am trying to model that I am not entirely sure how it functions. I am certain that it is a voltage monitor. It's basically a voltage divider (v_out = .017*v_in) enclosed in a grounded box with two holes on either side for the connections to the...

Hello all. I am conducting a simple research project, and am having a little trouble with the math for paschen's law. my question is. At 74762 Microns of pressure, using pure Neon gas, what is the electrode spacing in mm for the minimum breakdown voltage of that gas? Thank you.

I was getting a bit confused with Ohm's law, and the relationship between the current, resistance and voltage/potential difference? From my understanding, current and voltage both increase or decrease together, while current and resistance do the opposite? I was then wondering if there was any...

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...

Homework Statement Homework Equations What makes the shape circular/ parabolic? what determines the direction? The Attempt at a Solution Because the furthermost plate is positive, the proton would be repelled towards the screen, so i or iii. How do I know the shape?

I know that the equation F = CQ1Q2/r^2 can be rearranged to give electric field measured in volts per meter and then arearranged to get voltage but I don’t thing the answers I get are correct. I once got 10^9 volts between 2 coulombs 2 meters apart? I am really confused please help.

Homework Statement Calculate the electric field given by a voltage drop of 1 V across an insulator with thickness 20 nm. 2. The attempt at a solution I am not sure which formula to use in order to obtain the electric field. I think one should use the formula E=U/d, where E denotes the...

Homework Statement Homework EquationsThe Attempt at a Solution When we will move the contact X towards P, the potential difference should be maximum across the potential divider. I work out A as my answer but I think it is wrong.

Which is higher, the breakdown voltage if the electric field is uniform or the breakdown voltage if the electric field is non-uniform ?

Homework Statement I'm asked to find the voltage, current, and resistance through each resistor in the given circuit. Homework Equations Req for parallel = 1/R1 + 1/R2 + ... Req for series = R1 + R2 + ... The Attempt at a Solution First, I want to find the total resistance in the circuit...

Homework Statement I was going through this PDF on my own to review for my AP Physics C E&M exam: https://apcentral.collegeboard.org/pdf/ap-physics-c-e-m-frq-2017.pdf?course=ap-physics-c-electricity-and-magnetism I was also watching this video (which discusses the solutions): The part I am...

Say I have two parallel conductors that are both L long and d distance apart (center to center). I run AC power of frequency f and RMS voltage V through one conductor. That current will create a fluctuating magnetic field which will pass through the the other conductor and generate a voltage...

I am wondering whether electrons have a net motion against an applied constant electric field in a conductor. Intuition tells me that "of course they should", but so far the math has shown me otherwise. Here are my current thoughts: 1) I cannot rely on the obsolute Drude's model. What's more...

Hi...Here is a GIF of some electrical explosions that I recorded with my full spectrum camera. These power lines supply power to a neighboring county so it didn't affect my area. In the upper atmosphere we see something similar in Transient Luminous Events (TLEs). In the case of the blue in Blue...

Homework Statement Homework Equations Vab =| Σ IR - Σ ε | The Attempt at a Solution Vab = | - 0.2*2 - (-12) | = 11.6 V Can somebody check my answer please ?

I'm having trouble understanding how voltage drops. My understanding of voltage is a difference in potential, with potential being how much work is necessary to move a test charge to a specific orientation. So, if we have a circuit with say, a 12V battery and a 1 ohm resistor, and I had a +1...

Homework Statement You have a voltmeter with an internal resistance of 10 MΩ. You would like to measure a very large voltage source, but you notice that this overwhelms your voltmeter, and you begin to get inaccurate results if the voltage is too high. You design the circuit shown above as a...

Hi, I was wondering about saturation current in the photoelectric effect. It is clear to me that for a sufficiently large accelerating potential all of the electrons are gathered by the collecting electrode. Since it is all of them, there cannot be more, and the current won't change if the...

Homework Statement Homework EquationsThe Attempt at a Solution I don't understand why would the current be zero in any of the branches . May be I am missing something very fundamental . Please help me understand this question .

Homework Statement Homework Equations Kirchoff's Rule The sum of all V = 0 The Attempt at a Solution [/B] I think I'm having a problem determining the current at r_2 and R_3. I had originally thought the currents at both resistors would be I_3, writing E_2 — r_2 I_3 — R_3 I_3 — I_1 R_1 = 0...

Say I have two parallel conductors that are both L long and d distance apart (center to center). I run AC power of frequency f and RMS voltage V through one conductor. That current will create a fluctuating magnetic field which will pass through the the other conductor and generate a voltage...

I have done an experimeny to investigate how the voltage across a capacitor, Vc varies as it charges and to find the capacitive time constant in a DC RC circuits and Study resonance in an AC inductor-capacitor circuit (AC LRC circuit). I am now having trouble in writing the source of error of...

Hi, I have an air wound 0.736 mH coil in series with a 3.5pF capacitor being driven with a function generator. Ideally the series resonant frequency should be around 3.13 MHz. The internal impedance of the function generator is 50 ohms or so. At resonance the voltage across the cap should be...

Homework Statement An AFM uses a quadrant photo-diode to measure the deflection of the laser beam. Sketch the voltage in quadrants A, B, C and D as the tip travels on top of a single carbon nano-tube resting on a flat surface when the AFM is operating on tapping mode. Homework Equations Not...

Hello guys, I have designed and built a prototype with the aid of PI Expert Designer tool according to the following characteristics: - Vinput = 85-305Vac - Voutput / Ioutput = 12Vdc / +700mAdc I also attach you the schematic of the converter, which was taken from DER-528 application note (14...

Homework Statement A wire with conductivity σ carries current I. The current is increasing at the rate dI/dt. Show that there is a displacement current in the wire equal to e0/σ⋅dI/dt Homework Equations Id = e0⋅dφ/dt dφ/dt = dE/dt ⋅ A (This is usually true, I'm not sure if it's useful in...

Consider a solid material such as a conductor. I would like to know if there are ways to determine the voltage at specific spots on the material, without plugging a metallic wire and connect it to a voltmeter. I know voltage is relative and I'm interested in checking voltage differences across...

Hi! I'm working on a project in which a small microcontroller with a max. analog input of 5v takes readings from multiple sensors. I would like to make this input window a bit more versatile, and turned to voltage dividers as a solution. 'Problem is, I'm having a bit of trouble understanding how...

I understand that magnetic flux density is measured in Teslas or Weber’s per square meter and that voltage or emf is measured using faraday’s law of induction which is E= - N dφ/dt Where N= number parallel fields Φ = magnetic flux (Wb) E= emf (V) What I don’t understand is the time function...

Homework Statement I am very lost, I tried everything I can do to find the voltage/stored energy for each capacitor, but no luck. I know that for parallel, V1=V2=V3 etc and stored energy is Q1+Q2 etc. And for series it's the opposite, but I'm getting completely different numbers for both of...

Hello, I read article how to check battery condition appropriately (e.g. car battery). (Link: https://www.allaboutcircuits.com/textbook/direct-current/chpt-11/battery-ratings/ ) It's written that: in order to get better results, one must check under load. I'm not EE - I study physics and...

Homework Statement Consider a conducting sphere with radius ##R## connected to a voltage source of ##V_0## volts. If the sphere is then covered by a dielectric spherical layer of radius ##9R## calculated the relative permitivitty ##\varepsilon_0## needed so that the field in the empty zone...

Homework Statement For a lab, we explored Kirchhoff's Laws. I made a procedural mistake while measuring my voltage values across my different elements. I know that all of my calculated voltage sums are correct, so I was wondering what I might have done to have loops ACBA and CDBC have almost...

Why is the electrical potential greater before it passes through a resistor than after?

I'm trying to figure out how to calculate how much energy is stored in a battery between certain voltages. I know capacity is traditionally calculated by multiplying amps drawn by nominal voltage by time, but this seems like an approximation because voltage decreases as the battery is...

Homework Statement decreasing the resistance increases the current if the voltage remains unchanged. Homework Equations V=IR The Attempt at a Solution The solution in the book does not count this as a true statement, but it seems true to me. Is there any reason why the statement would be false?

in a circuit like the one in the attached picture, the voltage between two points in between two resistors should be 0. But there is current flowing through the circuit. So what’s going on here? Does ohms law not apply in this situation for some reason?

If I had a simple series circuit with only a single resistor, and I used a voltmeter to find the voltage between a point at the end of the circuit and another point, which was moved from the beginning to the end of the circuit, what would I find at these various point? Would the voltage remain...

Homework Statement Homework EquationsThe Attempt at a Solution Since both D1 and D2 are forward biased for the positive half cycle for the voltage input , current will flow through them . Both the diodes offer very little resistance , but do they act like connecting wires when forward biased...

Homework Statement Homework EquationsThe Attempt at a Solution I am assuming that the given value of voltage applied is an RMS value . Same voltage is applied across both the branches . In the upper branch the net resistance is the sum of capacitive reactance of the capacitor and...

Hi all, I am planning to install two Peltier tiles( TEC-12706 ) to an electric toothbrush which runs solely on the heat of human hand. I have tested the tile and it can generate about 150 millivolts, which is not sufficient to power a 12V DC electric motor. I think I should get a transformer or...

Homework Statement Alright, this is a Lab Exercise, so it's light on an actual introduction and data, but I'll do my best to put into words the whole thing. The gist of it is that we have a Vat with water, a millimetre paper at the bottom, and we put two Equipotential surfaces inside. We charge...

Homework Statement I have to write about voltage within a parallel circuit and the formula for voltage in parallel is Vt=V1=V2=V3. But I was wondering if that's only the case if the resistors have the same resistance becasue I used resistors with different values Homework Equations V1=V2=V3...

Hi everyone, I'm new to this forum so I apologise in advance if I may have posted in the wrong forum or made a similar error. I recently conducted an experiment with some peers where we measured the voltage across a charging capacitor in an RC circuit over a period of time. The diagram is...

[FONT=verdana]Dear Everybody, Using the exact exponential treatment, find how much time (in s) is required to charge an initially uncharged [FONT=verdana]140 pF[FONT=verdana] capacitor (C) through a [FONT=verdana]77.0 M[FONT=&quot]Ω[FONT=verdana] resistor (R) to...