Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [electric-circuits]

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

-1
votes
0answers
18 views

RC circuit Laplace Transform [on hold]

I've got the equation for RC circuit: where F[s] was initially $e(t) = V_{0} sin(ωt)$ before Laplace Transform. How to calculate function $V_{2}(f)$, where $f$ is the frequency?
0
votes
1answer
28 views

Electron gun design

I have a question about electron guns. I have read a lot, and all designs use high NEGATIVE voltage ($-1000$ V for example). Is possible to use high POSITIVE voltage like this drawing? Or do you think ...
-2
votes
0answers
16 views

What is the current in the resistor X? [on hold]

A combination of four identical resistors each of resistance R are connected to a source of emf ε of negligible internal resistance. What is the current in the resistor X.
0
votes
0answers
24 views

Question about the purpose of a transistor [migrated]

I've been studying about diodes and transistors and something made me wonder about the purpose of transistors. In the examples we were talking about increasing current by using two batteries with a ...
0
votes
0answers
23 views

Evaluating current flow in circuit [on hold]

How to find the flow of charge in each prong of the circuit.
0
votes
0answers
24 views

Connecting one lead of capacitor to a certain charged object (to get a potential difference)

Setup-A charged sphere , connected to one plate of capacitor , other lead of capacitor is free. Question-Will the capacitor plates go through a charge redistribution ? Arguments/Counterarguments-I ...
1
vote
3answers
69 views

Is a complete circuit required for capacitors to redistribute charges?

Suppose I have two capacitors of different capacitance $C_1$, $C_2$and they have been charged prior connecting by voltage of $V_1$ and $V_2$ respectively the positive plate of one capacitor is ...
0
votes
1answer
24 views

How does the thickness of a sample affect the accuracy of four-point probe resistance measurements?

I have been reading up on my experimental techniques, and I found a description of four terminal sensing here. It makes the statement that for accurate measurement of resistance the thickness of the ...
0
votes
0answers
32 views

Adequate Power Supply for 300 Daisy-Chained LEDs [migrated]

I have 300 LEDs (ws2812b) wired in a series. They were sold as 150 LED/5 meters and rated to power at 9W/m, so 45W/5m strip. I would need 90 Watts to power my entire 300 LED strip. I have a 3-rail ...
0
votes
1answer
39 views

Why the $L$ in an $RLC$ circuit? [duplicate]

I was studying for a differential equations class and came upon some information about $RLC$ circuits. I know the $R$ stands for resistance (makes sense) and $C$ stands for capacitor (this also makes ...
-1
votes
1answer
33 views

Current direction in an electric circuit

in the picture, in the circuit 1, we can see the conventional current direction in the cirucit 2, we can see the real electrons direction it is right i think. but then i have a big problem, during ...
0
votes
0answers
19 views

Open circuit voltage gain of JFET transistor circuit [migrated]

So this is one of the questions from my previous past papers, I worked out my Vgs and Vds value correctly (-1.25v and 10v). However, when calculating my open circuit voltage gain, I use the quetion Av=...
-2
votes
0answers
56 views

can I be reproached for something if I draw a circuit in a circle? [on hold]

can I be reproached for something if I draw an eletric circuit in a circle? normally we draw electric circuit with rectangle. so if i draw an eletric circuit with a circle, could someone say something ...
0
votes
0answers
29 views

How to use energy conservation in following case [duplicate]

A capacitor of capacitance C is intially uncharged is connected with a battery of emf ε.Find the heat dissipated in the circuit during charging?How can we apply energy conservation although there are ...
2
votes
2answers
41 views

Does current flow in the wire when only one terminal of the battery is earthed?

Let me specify beforehand that this question has been asked previously but I haven't been able to satisfy my curiosity.I know a battery maintains a potential difference between it's terminals , let's ...
0
votes
1answer
29 views

Work done in moving a charge in circuit?

Why is the work done in moving a charge from one point to another in a circuit through any path the same even though heat and other losses are there?
1
vote
2answers
44 views

I inserted my DC toy motor into and AC power outlet. Sparking happened and the motor isn't working anymore. What exactly happened?

What took place inside the motor and why isn't it working anymore? I familiar with basic electricity and circuits, but can somebody explain it in easy language.
2
votes
0answers
22 views

Finding the voltage across an inductor when opening the switch [on hold]

Well, I've the following circuit: In the circuit I want to find the voltage $\text{V}_{\text{Y}_1}\left(t\right)$ as a function of time, after I open the switch (this switch was closed 'forever' ...
0
votes
1answer
25 views

Transient state analysis of RL circuit

A circuit consists of an ideal battery an ideal inductor and zero resistance. The value of inductance is $4$H and the battery has an emf of $2$V. There is fuse in the circuit which breaks after when ...
0
votes
1answer
26 views

RC circuit: is order of resistance and capacitor important?

in a RC circuit is order of resistance and capacitor important? Typically there is the battery then the capacitor then the resistance, but is it ok if I draw with the battery then the resistance and ...
0
votes
2answers
55 views

Work done by battery?

Why the work done by a battery is Q*V where V is emf of battery and Q is charge that is made to flow in circuit?please explain detail? explain and write the formulas
0
votes
2answers
46 views

Impedance of an LCR circuit

So I am trying to understand how to find the impedance of the parallel LC component of this filter circuit. I am given that the transfer function $\mathbf{T}_C = \dfrac{\mathbf{V}_{out}}{\mathbf{V}_{...
0
votes
0answers
26 views

Origin of Josephson voltage equation?

i cant find a satisfying explanation, and I cant figure it out myself, a derivation for the josephson equation: $$U(t)=\frac{\hbar}{2e}\frac{d\phi}{dt}$$ where $U(t)$ is the voltage, and $\phi$ is the ...
0
votes
1answer
28 views

Overestimation Problem [duplicate]

I had asked this problem earlier but I was too vague in how I asked it so I'm making a new post to be more specific. Problem: Say we have a series circuit with an ammeter, a cell with internal ...
4
votes
1answer
40 views

How can the Neutral wire be 0V if its AC? [duplicate]

So I understand Alternating current like a battery, in which the Poles are constantly changed out, so the circuit stays completed, but the electrons change directions. But how can then in an AC plug ...
0
votes
1answer
14 views

Inductors in parallel circuits

I recently encountered this problem dealing with inductors, similar to the diagram below. The switch is closed for a long period of time. I know that eventually the inductor and act like a short, ...
7
votes
4answers
1k views

Why is there no current between two capacitors connected in series?

I want to ask a question about the figure below. Why the current does not flow from $-Q$ term to $+Q$ term or from a to b since there is a voltage?
0
votes
1answer
26 views

When the external resistor increases in temperature, why is the calculated value for internal resistance higher?

Say we had a circuit with a cell (with internal resistance)and an external resistor of 10 ohms as shown: The 10 ohm resistor then increases in temperature, leading to an increase in resistance in ...
0
votes
0answers
20 views

Glass in a circuit? [closed]

How glass would be connected to a circuit containing ammeter, voltmeter and a power supply? I think electrodes would be connected at areas perpendicular to flow to of current in circuit but don’t know ...
1
vote
5answers
83 views

Why does the potential difference across a type of parallel circuit not act like a potential divider?

Image credit (Q3) In this attached circuit, when $R_1=0\Omega$, I am failing to understand how the two cells affect the potential difference across the central resistor R3. I understand that ...
3
votes
5answers
722 views

Isn't Kirchhoff's junction law a violation of conservation of charge?

As a beginner of classical electrodynamics I am quite confused in understanding Kirchhoff's junction law or it may be the reason that I misunderstood the law of conservation of charge.Please correct ...
0
votes
2answers
63 views

Does Kirchhoff's rule break down as it applies to capacitors

A homework problem asked me to find the voltage across a series of capacitors after they came to equilibrium. Essentially a capacitor C1 with a capacitance of 6.0 F is charged until the potential ...
0
votes
3answers
66 views

Voltmeter reads zero with two same batteries connected in series [closed]

this is an a level physics question, can someone here please explain why voltmeter reads zero and how changing resistance of variable resistor effects voltmeter reading. The main concept i want to ...
0
votes
5answers
80 views

If current through a resistor is zero, does the circuit break?

I'm really confused. I'm studying about how capacitors are charged, and I learnt that there's a resistor attached in series with the capacitor when it is being charged. When the capacitor is fully ...
1
vote
0answers
12 views

Photoresistor in Parallel [closed]

I am currently building a photoresistor from a kit that I bought a few months ago. I had a few questions when I was building this circuit: What happens when you wire the photoresistor in parallel ...
0
votes
3answers
59 views

Charging capacitor in an incomplete circuit [closed]

I have 2 confused questions regarding the below circuit. please help me out How will the capacitor even charge in the following scenario when the right side of the capacitor is not connected to ...
0
votes
1answer
44 views

Evaporating tungsten wire

Consider an incandescent bulb having a thin filament of tungsten that is heated to high temperature by passing an electric current. The hot filament emits black-body radiation. The filament is ...
1
vote
0answers
16 views

Why does the base-emitter voltage in NPN transistor become constant

The setup above shows the experiment that I have been working with. During the experiment, the current $i_c$ and the voltage $V_{be}$ were measured for increasing $V_{in}$. At some point, the current ...
0
votes
1answer
40 views

Neglecting capacitor from circuit

Take a look at this circuit : This question is answered in $Serway$ $7th$ ,And the book neglected 8 Farad capacitor because the voltage between $c$ and $d$ is zero. My questions is : $1.$Should not ...
0
votes
1answer
26 views

How can we analyze electronic capacitors in series? [closed]

Two capacitors are in series, such as in this circuit diagram: When doing a circuit analysis, how can we describe the voltages and charges across the two capacitors?
0
votes
3answers
42 views

Current Divider rule

If you have two resistors $R_{A},R_{B}$ connected in parallel with a battery, you can find the current that flows through one resistor ex.$R_{A}$ using the current divider rule: $$I_{A}=\frac{V_{T}}{...
0
votes
0answers
35 views

Estimating the effect of inductors in an RL circuit

I'm trying to understand how an inductor works in an RL circuit. When I use an air core inductor, my estimation is fairly accurate to the test circuit but as soon as I use an inductor with a core, the ...
1
vote
1answer
99 views

I got this formula but can anyone prove it [closed]

Yesterday while doing some questions, I came across a formula that if a wire with uniform resistance R is made into n sided regular polygon then the net resistance between any two corners with $x-1$ ...
4
votes
2answers
100 views

Why does electrical resistivity have units of $\Omega \cdot \mathrm{m}$ rather than $\Omega \cdot \mathrm{m}^3 ?$

Electrical resistivity has units of $\Omega \cdot \mathrm{m} .$ However, since resistivity can be described as the resistance of a unit cube, shouldn't the units therefore be $\Omega \cdot \mathrm{m}^...
-1
votes
3answers
105 views

How does resistance affect the voltage drop? [closed]

There is a series curcuit and there are 5 resistors in it which are the light bulbs. I know that current is directly proportional to the voltage and inversely proportional to the resistance. Can ...
0
votes
1answer
41 views

Redrawing circuit rules

Take a look at this circuit: Is it allowable to redraw the circuit like this ? Can I move cd wire until it merge with b junction ? Can I move e point like what I did in the figure ?If yes why this ...
0
votes
0answers
25 views

Stochastic version of the Kirchoff circuit law

I assume this question could be written in a non-technical jargon, but I will try to be as simple as possible. The Kirchoff circuits law assert that the sum of inward and outward currents at a node ...
0
votes
1answer
27 views

Magnetic Circuits: Why is magnetic Flux constant through one loop of a magnetic Circuit?

Wikipedia states that for a magnetic circuit, the magnetic flux throughout the path of the circuit is constant. If I understand right, this means that \begin{align} \Phi_1 = \Phi_2 = \Phi_3 = \Phi_4 =...
0
votes
2answers
45 views

Parallel circuits at home

My textbook states that if you have a light bulb turned on and you connected a hair dryer with it in parallel, then the brightness of the light bulb will decrease. The reason my textbook provided, ...
0
votes
2answers
73 views

Why I can't find a value for the resistivity of plastic? [closed]

I'm working to a relation about resistence of various materials. I haven't found a table of resistivity wich includes Plastic. Is searching plastic too general? Does a table in which there is at least ...