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

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Circuit with capacitor and two resistors - total current - charge - differential equation [closed]

Consider the circuit below consisting out of a capacitor C and two identical resistors R. For $t<0$ the switch is open and the capacitor is uncharged. At $t=0$ switch is shut and the circuit is ...
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1answer
56 views

Loss in energy while charging a capacitor

Suppose a capacitor having capacitance $C$ is being charged using a cell of emf $E$. By the time the capacitor is fully charged, the cell has supplied $QV$ energy while the potential energy of the ...
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2answers
393 views

Energy conservation when capacitor charges in a zero resistance circuit

We know that when a capacitor charges from a source $E$, it stores energy of $E=\frac{1}{2}QV $. This is derived without taking into consideration any resistances present in the circuit. We also ...
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0answers
33 views

Maximum current in LC Circuits

Two capacitors of capacitance $C$ and $3C$ are charged to potential difference $V_o$ and $2V_o$ respectively and connected to an inductor, all three in series. Now the switch S is closed. Find the ...
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0answers
34 views

What is the form of the skin effect in exponentially decreasing (or exponentially increasing) voltages?

I tried to replicate the standard derivation of the skin effect for exponentially shrinking or growing voltages (idealize the surface of the wire as a half-infinite volume of conductor) but I'm not ...
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1answer
68 views

How uniquely determined is the impedance of an infinite-chain circuit?

A recent question asked how to find the impedance of an infinite chain of series-plus-parallel circuits. The standard trick is to split the chain after the first link, and treat the tail of the ...
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5answers
104 views

Why is $R_2$ and $ R_3$ parallel with $R_1$ in this circuit?

I know that if $V_2$ wasn't there it would make sense if $R_2$ and $R_3$ were parallel with each other and in series with $R_1$. Why is it different in this case?
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2answers
137 views

Why does voltage change in series circuit but not in parallel circuit?

Voltage divides after every resistor in series but not when placed in parallel. Please explain this with using very less or no mathematical equations. I have tried searching for an answer online but ...
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1answer
26 views

How is this trigonometric substitution achieved for this simple capacitor circuit equation?

In a simple circuit with one capacitor and one AC source, where the equation of the source voltage is v(t) = Acos(ωt), I was trying to follow how they found the ...
5
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2answers
334 views

Modeling stochastic process with frequency-dependent power spectrum

I'm trying to model of Johnson-Nyquist noise propagation in a nonlinear circuit. An ideal (linear) resistor can be modeled very nicely by the Fokker-Planck equation (equivalently, the drift-diffusion ...
2
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1answer
207 views

Kirchhoff current loop in Resistor Diode Ladder network

I am looking for an approach on how to apply Kirchhoff current / voltage law in the infinitely long diode ladder network. Can anyone help me with this ? I am looking for 1D differential equation or ...
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1answer
55 views

Impedance of the infinitely long circuit

Is there a way to find impedance of the infinite circuit like this? It will be much simpler if one has either parallel or series combination but here is both.
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4answers
2k views

What are the effects of cosmic rays on consumer electronics? [closed]

When electronics/computer companies design a new chip, processor/ memory card/ or a solar cell, do they study the effect of cosmic rays on such electronically sensitive materials? If not, why not?
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1answer
30 views

Current - Voltage curve for non-ohmic material

Forgive me for I am a math student and am quite ignorant in these topics. I would like to know, at least implicitly, how the current intensity of a lightbulb, for example, relates to the potential ...
3
votes
4answers
324 views

The electric field in wires in a circuit

I have a hard time really understanding the electric field in a complete curcuit. How is the electric field maintained throughout the wiring / the conductors from component to component? The charges ...
1
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1answer
41 views

DIY Ring Light: Grounding Bulbs in Circuit

I'm looking at making a DIY ring light using multiple fluorescent light bulbs. I'm in New Zealand and we get 230-240V and an current of 10A. I know from this I could rig up to 24 100W bulbs in series ...
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1answer
19 views

How does static protection really work?

I've read that while working with circuits you want your body to stay at the same voltage as the components you are trying to protect. So you're supposed to connect those wrist things to one of the ...
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2answers
55 views

Please give your valuable opinion in this capacitor problem! [closed]

The plates of a parallel capacitor are given charges +4Q and -2QThe capacitor is then connected across an uncharged capacitor of same capacitance C. What is the final potential difference between ...
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2answers
53 views

According to calculations why the current of a battery of a mobile is high?

If you pay attention to the features of your mobile's battery the voltage would be around 3-4V and power is 4-5 Wh (14400-18000 Ws) and with calculating the current you can find a very high ...
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2answers
47 views

Why the electric potential energy the charges carry in a electric circuit does not vary with its distance to the opposite terminal?

I understand that with wires assumed to be ideal, there is no resistance and subsequently no force acting on electrons, hence no work done and p.d. across any segment of wire. However, as the ...
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3answers
73 views

What is the voltage at every pair of points along a ideal wire that is connecting the two terminals of a battery?

If you stick a wire across a battery, obviously it is going to discharge the battery. This will be due to a voltage difference between the two terminals. However, the equation $V = IR$ tells you how ...
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0answers
52 views

Ampere's law and magnetic circuit

For magnetic circuit there is an equation NI=HL. This equation is obtained by applying Ampere's law. H is magnetic field intensity and L is the length of the circuit. In following picture the equation ...
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3answers
68 views

Electricity series connection of resistor

In simple circuit is current in wire different from current in resistor as wire also opposes the flow of electrons so wire should also be added in series connection of resistor
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1answer
60 views

Does an Inductor maintain it's energy?

Consider a simple LCR ac circuit; generally I (might) understand that the charge exchange between capacitor and inductor would induce a harmonic current flow, but I remain confused for two reasons: ...
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1answer
30 views

Electricity parallel combination

Why is resistance lower in a parallel configuration and therefore current is more? Shouldn't resistance be addition of all resistor's resistance?
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2answers
62 views

How long do electrons take to “decide” how to go through a circuit?

Many other people have asked how an electron decides which path to take, but no one has asked how long do they take. Is there an equation for their "uncertainty" time? Do they decide instantaneously ...
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0answers
30 views

Occurance and disappearance of degeneneracies in a periodic structure of (quantum) LC circuits

Introductory part I'm currently studying an analytical model of coupled LC circuits, in preparation for actually performing measurements on such structures. While the final goal will struggle with a ...
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1answer
28 views

can a power supply with high voltage value and some current be split into multiple small voltages of same current?

For example: if I have a source that can give an output of 10,000 Volts with some unknown current value, now, can i make that 10,000 Volts to 50 (need not be 50 exactly but maybe more than 30) of 200 ...
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6answers
11k views

What would be the effective resistance of the ladder of resistors having n steps

I'm a tutor. This is a high school level problem. In high school, every one have might have solved a problem of effective resistance of a ladder of resistors having infinite steps. Now the problem is ...
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2answers
51 views

Why does electrical impedance have as many parameters as it has?

The impedance of a circuit is written: $$ Z(R,L,C,f) = R + j ( 2 \pi f L - \frac{1}{2 \pi f C} ). $$ What is the line of thinking that frequency, resistance, capacitance, and inductance are the only ...
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7answers
11k views

Does a current carrying wire produce electric field outside?

In the modern texts of electromagnetism in the presence of stationary currents the electric field is assumed conservative $\nabla \times E =0 $. Using this we get $E_{||}^{out}=E_{||}^{in}$ which ...
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3answers
44 views

Effect on capacitance when capacitor number increased [closed]

What happens to total charge and potential difference when number of capacitors increased in series and parallel combination? My question in text book is: Initially, a single capacitance $C_1$ is ...
5
votes
4answers
10k views

Is it possible to flow current in open circuit?

As I know a battery is an example of a closed circuit where it can then produce electricity , electrons will flow from negative pole to positive. A chemistry representation of this battery is for ...
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2answers
43 views

Quality Factor in a Parallel LC Circuit

I was wondering if there is a notion of a quality factor in a parallel LC circuit, since there is no resistance. One can show that this circuit has a resonance frequency as follows: Impedance: ...
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1answer
33 views

AC pass through capacitor

I am confused how AC pass through a capacitor? Can any one explain or have the vedio how AC pass through capacitor?
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0answers
34 views

What exactly happens in an electric circuit?

After reading chapters on Electrostatics, I have been having lots of problems in understanding current electricity.I will be trying to tell what my problems are by telling what I already know.Please ...
5
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4answers
1k views

How can there be a current and an electric field in an idealized wire with no voltage drop?

In an ideal circuit, How can there be a current b/w points a & b, when there is no potential difference and thus no electric field between a & b? If there is no current, then where does ...
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2answers
2k views

How do Zener diodes work?

I was going through some of the theory behind Zener diodes. I know what they're used to work at constant voltage, but I don't know how they work. Actually, I kind of get that too, I know that voltage ...
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0answers
28 views

Initial current, RC Circuit

The task goes like this: The voltage between the points A and B, in the circuit diagram below, is 100 V. What's the initial current through the resistor when we close the switch S? (Other components - ...
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4answers
204 views

Ohm's Law Question?

Since $V=IR$, if you were to have say a $5\:\mathrm{V}$ source connected directly to ground, no components in the circuit at all, you would need to add resistance for the current to flow? Or is there ...
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3answers
106 views

Why does the resistance halve when two resistors of equal resistance are in parallel? [closed]

This is the question and answer to a homework question and I do not understand why this is the case. What is the logic behind it?
0
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1answer
55 views

Equivalent Resistance [duplicate]

I've never had problems in finding the $R_{eq}$ of a circuit, but in this case I don't really know how to do it:
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1answer
341 views

What does a negative Thevenin-equivalent resistance mean?

What is the physical meaning of negative value of "Thevenin" resistance? Sometimes in the calculations, a negative value of Thevenin resistance appears.
0
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1answer
70 views

Confusion with potential difference [closed]

I was trying to solve a hard problem involving a circuit like this: Find the reading on the voltmeter (red ones are resistors) I don't know how to think about potential difference across branches ...
0
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2answers
84 views

Calculating the energy supplied by a battery

If you wanted to calculate the energy supplied by a battery in time $t$ you would use $E=VIt$ where $I$ is the current through the battery. If the internal resistance is $r$ we could also use ...
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1answer
492 views

Non-conservative Electric Field

I was watching this video from Walter Lewin and while watching these two videos, I noticed there is a "contradiction" in what he is doing. All links direct you exactly to where he begins, so you don't ...
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1answer
50 views

Experiment for finding resistivity

I was reading an experiment to measure the resistivity of a wire. I understand everything except for why the variable resistor is connected to the side of the positive terminal of the battery. Since ...
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1answer
48 views

Calculating resistances in parallel

I was playing around with a question involving resistances in parallel. I realized that $n$ equal resistors (resistance $R$) in parallel have combined resistance $R/n$. I proved this using ...
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2answers
1k views

Why does current need a closed loop to flow?

My textbooks at the moment don't really explain the underlying theory of circuits. All I do is apply the rules I was taught when I solve these problems. I don't get why electrons need to have a closed ...
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2answers
52 views

Resistors in parallel: How do I make this rigorous? [closed]

In my revision guide it says "when two resistors are in parallel, the current has two paths it can flow through so there is less opposition to the current. This is why the combined resistance is less ...