An electronic system, with closed loop current flow, and relative electrical potentials present across electrical components.

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Capacitance question

A capacitors capacitance, C is equal to Q/V right? If Q was somehow cut in half, would the potential difference also be cut in half, since V is directly proportional to Q? And if so, Its C would be ...
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65 views

Internal resistance of a battery

It is my understanding that internal resistance of the battery is mainly due to resistance of its electrodes and electrolytes. During the charge or discharge of the battery, there's a potential drop $\...
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161 views

Determine brightness of bulbs in a sImple parallel circuit [closed]

I have a parallel/series circuit given in the following link: The question, listed here: Suppose that you were to unscrew light bulb $L3$. what would happen to the other bulbs? A. $L3$, $...
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36 views

Simple two volt source circuit - Current [closed]

THIS CIRCUIT: A=5.6 kΩ , B=5.6 kΩ, and C=10 kΩ. How the HECK do I find the currents through each resistor? Absolutely no clue. Note: I understand Kirchhoff's Laws and Ohm's Law perfectly well - ...
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125 views

Where does a straight conducting wire get its capacitance?

If I take a simple piece of conducting wire (of which I can calculate the resistance from the wire dimensions and resistivity of the wire material) and connect it across the terminals of a battery of ...
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44 views

Can there be an electric current drawn through a resistor from just one terminal of a battery?

The question will appear a little more sincere from the attached diagram. Will there be any flow of charge at all once the switch S is closed? If yes, then by what mechanism? for how long? What ...
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17 views

Phase angle of a circuit

Above is the problem at hand. I know how to calculate the angular frequency and total impedance of the circuit given the information provided. However, I'm not really sure what the question is asking, ...
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24 views

Setting up current directions in multiloop circuits with more than one battery

I'm currently working on this problem: I must find the current in each battery. I have certain doubts when estipulating the currents: How many $i$ exists in this problem? The current going in a ...
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64 views

Why does a capacitor in an AC circuit allow a lamp to glow continuously

How does the capacitor allow the lamp to glow continuously, but would not do so if the circuit was DC.
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93 views

How to detect if resistors are in parallel or series?

Some circuits are easier to see which resistors are in parallel or series. However, when faced with a more complex circuit, I can't figure out which ones are in series or parallel. I am currently ...
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810 views

Why do Capacitor Inductor circuits Oscillate instead of reaching equilibrium?

When the capacitor is fully charged there is a potential difference between its poles and that creates a current. This current would create a magnetic field that is changing in the Inductor (because ...
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53 views

Coupling of LC circuits

I am reading an old article in a physics journal in which the author explains that the frequency between two identical, but capacitively coupled oscillators becomes $\omega_\pm=\omega_0\sqrt{1\pm\...
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82 views

Visualising current in the LCR circuit

I just went through the theory of the serial LCR circuit. There current and voltage are 90 degrees out of phase with each other. Now I was trying to imagine an animation with just dots. And I ...
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53 views

Can a magnetic lock be negated or overcome by a stronger electro magnet? [closed]

Magnetic locks seem to be fairly standard on modern buildings. Is it, though, possible to negate a magnetic lock my placing an oppositely-polarized, strong electromagnet across from the magnets on the ...
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310 views

Steady-State Current

I am in the process of completing some homework and have come across a question that says: "What is the steady-state current?" It is asking in reference to a circuit that includes two capacitors in ...
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31 views

How can the response at the terminal end of an infinite ladder network be solved?

In a recent post: How can the transfer function of an infinite ladder network be used to solve real world problems? I reference how one can solve the transfer function (impedance) of an infinite ...
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How can the transfer function of an infinite ladder network be used to solve real world problems?

In his lectures on Physics, Feynman illustrates a mathematical 'trick' in formulating the impedance of an infinite ladder, LC network. It basically counts on the assumption that adding one more 'rung' ...
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23 views

Short Circuit Fires

I understand that if there’s low resistance, Ohm’s law shows that the current drawn will be very high. However, isn’t resistance what causes heat in a wire? I get there’s a lot of current going ...
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36 views

Open Circuits vs. Charging a Capacator

When you attach a capacitor to a battery via two wires, charge transfer occurs from one of the plates to the other. However, in an open circuit, there is infinite resistance in the dead-ended wire, ...
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25 views

How many electrons pased in electrical circuit

Assume I have electrical circuit that is connected to 5V power supply and current straight is 1A. How to know how many electrons are passed in single point per hour?
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If I lick a 9V battery, why doesn't my tongue noticeably get hotter?

Power dissipated is I^2*R, I don't know the resistance of my tongue so I can't tell how much current goes through my tongue. A resistor I have does get hot and I'm guessing it has a higher resistance ...
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64 views

Reference for Kirchhoff's Circuit Laws

Does anyone know the reference where Gustav Kirchhoff published his famous circuit laws?
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30 views

If a heater was turned on its' own wire, would heating of the wire cause the resistance to increase, thus the current into the heater to decrease?

I'm thinking not, because; A) It wouldn't make much sense in the real world because you'd need to avoid ever turning a heater towards its own wire, and you'd have to regulate the temperatures of any ...
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1k views

Significance of Time constants in LR and RC circuits [closed]

What is the significance of a time constant in a circuit? Is there any use of knowing the time at which the charge in a capacitor is 1-1/e times its total charge? What is special about the capacitor ...
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52 views

Thevenin theorem

Hi i got the trouble and i miss the concept about v out in thevenin i have the circuit like this so i used voltage divider for finding the voltage at point 1, but how to finding voltage at Vo , ...
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101 views

Current through moving bar on rails with non-constant magnetic field

I am working on the problem pictured below and I cannot figure it out. I have been using the equation d[flux]/dt = -BLv and V = -d[flux]/dt. However, since the magnetic field is not constant through ...
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42 views

How soon would electrons start flowing once I closed a switch on a circuit that was one light minute away from the battery

In a circuit, how do electrons "know" when the circuit is closed? To my understanding, they do not start flowing unless the circuit is closed. How soon would they start flowing once I closed a ...
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150 views

What happens in circuits where the propagation time of the electric field is significant?

Kirchhoff's current law assumes "that whenever current flows into one end of a conductor it immediately flows out the other end". I want to understand what happens when we cannot make this ...
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69 views

How big of a capacitor would I need to release 5 amps for 0.2 seconds? [closed]

Just what the title says, 5 amps for 0.2 seconds. Please bear in mind that I have absolutely no grasp on electrical wiring, so I would appreciate simple terms. What I need to do is release a burst of ...
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469 views

Capacitors in a series circuit with dielectric

When a dielectric slab is inserted between the plates of one of the two identical capacitors in Fig. 25-23, do the following properties of that capacitor increase, decrease, or remain the same: (a) ...
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69 views

How do i interpret the following electric potential diagrams?

We recently started to learn about electricity in school and I'm trying to understand the concept of voltage(potential differance). From what i understand, electrons flow from the negative terminal to ...
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63 views

What is voltage in a circuit?

What is voltage in a circuit? We just started learning about electricity in my school. From what I understand; potential is potential energy per Coulomb and voltage means difference in potential. So, ...
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54 views

Deriving Loop Equations in a Circuit with 2 batteries?

First time posting here, so please help with formatting. I need help deriving loop equations for this becaue the 2 batteries/power supplies are throwing me off. https://i.imgur.com/MJH6mIM.jpg The ...
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Given a large, multiloop circuit with resistors and batteries and I'm not sure how to simplify it. (When NOT to combine resistors?) [closed]

So here's the circuit, and the question is looking for current i: All resistors are 2 ohms and the batteries are 5 volts. I'm trying to apply the resistance combination Kurchov rules to make this ...
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42 views

Heat creation of computer electronics

The first thing I learnt in physics was that whenever anything happens heat is created. Irrespective of the process. With that in mind, electronics clearly create heat (ohmic heating I think?). But ...
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energy conservation in an electric circuit

Define a reactive (lossless) and reciprocal two-port by its impedance matrix $[Z]$, so that $[Z]+[\bar Z] = [0]$ and let the source impedance and open circuit source voltage be $Z_s$ and $V_s$ at ...
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72 views

Physical intuition behind the fact that current in an inductor lags behind the emf/voltage by $\frac{\pi}{2}$ in an AC circuit

What exactly is the reason that current through an inductor in an AC circuit acquires maximum value after quarter a time period ($\frac{T}{4}$) of the emf getting the max value?
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176 views

Inductive reactance 0 for dc current?

Inductive reactance: $$X_L=\omega L=2\pi f L$$ is the opposition to the flow of current by an inductor. Frequency $f$ being $0$ for a DC current, the inductive reactance too is $0$. But doesn't the ...
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45 views

Please explain the phrase 'resistance'?

When electrons move against the opposition of resistance, "friction" is generated. Just like mechanical friction, the friction produced by electrons flowing against a resistance manifests itself in ...
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122 views

Is this circuit a series or parallel circuit?

I saw a definition of a parallel circuit as a circuit with more than one path for current to flow. Is that the definition that's accepted? It seems like a good definition to me, but does that mean ...
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97 views

Finding the resistance of platinum wire [closed]

Im currently lost on solving this potentially simple electricty question and was wondering if anyone in this community could hint me or tell me which equations and why these equations would be ...
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59 views

Is there a way to draw a thermodynamic diagram analogous to an electrical schematic for simple ideal systems?

I have a small system in air (which should be part of the schematic), consisting of several cylinders within one another and contacting ideally at various spots. How do I model it as if it were an ...
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417 views

Why does all the current flow through a short circuit if its voltage drop is considered zero?

Path of least resistance vs. short circuit I know the path of least reisistance has been clarified already However, to derive the equations you need to assume that the voltage of each parallel ...
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42 views

magnetising the material using coil

I studied that when alternating current is passed through the coil ,the coil produce magnetic field (primary) as shown in figure,when any conducting material placed near to that field, eddy current ...
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389 views

Derivation of capacitive reactance

Let $Q(t)$ be the charge stored in a capacitor $C$ in $t$ time for alternating current. Now, $$\displaystyle Q(t)=Q(0)+\int_{0}^{t}I(t)dt\\=Q(0)+\int_{0}^{t}I_oe^{j\omega t}dt\\=Q(0)+\frac{I_oe^{j\...
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58 views

Voltage Circuit

I feel that I don't understand how voltage works in a circuit. I understand voltage to be electric potential energy per unit charge (kq/r). In the case of a circuit, electrons flow from low potential ...
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1answer
121 views

Must a universal motor always rotate at the frequency of the AC current?

So here I have a picture of a motor (I think it is a universal motor but I am not sure). My question is if this motor is connected to an A.C. supply, does it have to rotate at the frequency of the A.C....
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40 views

Filament lamp $(V,i)$ behavior between 0 and 1V

I was wondering why the behavior is more "chaotic" at 0~1V when compared to 2V+ (which is when it starts to glow).