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

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Total current of two sources in series? [closed]

Here is a question that a friend asked me. He had to an experiment in school and do some calculations afterwards. Those calculations require maximal current that the DC source can produce. He has ...
2
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2answers
366 views

How to find $\tau$ in this circuit?

1) 2) I know, that $$ τ = \frac{L}{R} $$ but what is $R$ in this formula? It seems to be the total resistance, but how to find it in 1) and 2)?
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1answer
147 views

Power in hydraulic analogy

In hydraulic analogy one compares electrical circuits with water circuits. For the electric case the formula $P = U \cdot I$ for the electric power holds. The analogous formula for water flow would ...
2
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1answer
84 views

Circuit Loop Law Doubt

In a circuit with a solenoid/inductor and a resistor and a battery . Books say that $\Sigma \Delta V=0$ around a closed loop . That means work done by electrostatic field per unit charge is $0$ ...
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1answer
178 views

Fitting a circuit scheme to a simpler model

I have to simulate the electric field within a gas filled discharge gap generated by a radio frequency voltage generator. The circuit, provided to me by the experimenters somewhat far away, is given ...
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1answer
79 views

Current in AC circuit

The problem is to find the current on the capacitor. $I''$ should be correct, but I don't know how to construct the formula for $I'$. I managed to get the value for $I_c$ using Thevenin and Norton ...
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2answers
4k views

What happens when non-equal voltages are put in parallel? [duplicate]

If two batteries, say 2 volts and 5 volts, are connected in parallel, are there any problems? The higher voltage will then want to flow out, but also towards the lower 2 volt battery end, right?
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1answer
65 views

Doubt on the analysis of $RC$ circuit

I'm studying $RC$ circuits and I'm in doubt on how to deal with one kind of situation. Well, first when we have simply a circuit with just one resistor and one capacitor in series, or a circuit that ...
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2answers
447 views

Equivalent RC circuit to a RRC circuit?

I'm in doubt about a situation that I've seen sometimes: imagine we have a resistor in parallel with a resistor and a capacitor in series. Since I don't know how to generate figures of circuits to ...
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1answer
96 views

Help Understanding Non-conservative Fields

While watching a video lecture, I became uncomfortable with the results, (around 35 mins). The professor draws an electric circuit with a 1V batter, and two resistors (1 and 9 ohms). He then ...
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2answers
1k views

Voltmeter forming a closed circuit

A battery is connected to a 10Ω resistor as shown in Figure 2. The emf (electromotive force) of the battery is 6.0 V. When the switch is open the voltmeter reads 6.0 V and when it is closed it ...
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2answers
8k views

Different batteries connected in parallel

If we have 2 batteries one of emf x and the other is of emf y and we connect them in series we get an effective emf of x+y. But what if we connect them in parallel, how to calculate the emf now?
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2answers
991 views

How does my hand amplify an FM radio signal?

I have a gizmo that broadcasts an FM radio signal from my phone's headphone socket to my car's radio antenna. Sometimes, there's another station on the same frequency with a stronger signal and my ...
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3answers
8k views

Why don't electric workers get electrocuted when only touching one wire? [duplicate]

I know that when electricians work on the poles on the streets, if they only touch one wire at a time they will be fine. However, from my understanding, the negative wire is connected to a large ...
2
votes
1answer
303 views

Experiment to find Ammeter Resistance [closed]

I've been studying experimental electrodynamics and I needed to describe an experiment to find the resistance of an ammeter if I just have the ammeter together with one voltmeter and a protection ...
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4answers
850 views

Resistors in Parallel

From my book: "A length of wire is cut into five equal pieces. The five pieces are then connected in parallel, with the resulting resistance being 2.00 Ω. What was the resistance of the ...
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4answers
3k views

Capacitor Charging and Discharging when connected to the ground

When we charge a capacitor using a battery and then remove the battery, the plates of capacitor becomes charged. One holds positive charge and the other one gets equal negative charge. o. k. ? Now ...
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0answers
60 views

Capacitors discharging in series [duplicate]

If you connect positive plate of a charged capacitor to ground, it doesn't get discharged. Now consider $4$ capacitors of equal capacitance connected in series to a $10\, \mathrm{V}$ battery. Connect ...
2
votes
1answer
475 views

How we approach RLC circult from RLGC model?

In the text, it introduces a practical model to investigate a transmission line (like BNC cable), it considers the transmission line has resistive $R$, inductance $L$, conductance $G$ and capacitance ...
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1answer
275 views

Finding the Steady State Charges

Here the problem states to find the steady state charges on the condensers.<<<< According to me the charges on second at steady must be ...
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3answers
188 views

Impedance of a circuit [closed]

I am trying the following problem. A resistor with $295\Omega$ and an inductor are connected in series across an AC source that has voltage amplitude of $550V$. The rate at which electrical energy is ...
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3answers
153 views

Voltage of open circuit

A battery with emf $\varepsilon$ and internal resistance $r$ is connected with a resistor $R$ in the following open circuit. What is the voltage $V_{ab}=V_a-V_b$? The answer is $- ...
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1answer
597 views

measuring electromagnetic induction

There is a famous law which says that a potential difference is produced across a conductor when it is exposed to a varying MF. But, how do you measure it to prove? It is quite practical. ...
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4answers
1k views

When does Thevenin's theorem not apply (modelling a power source with a ohmic internal resistance)

Most physics text books say that a power source can be modelled as an EMF with a internal resistance. This is also know as Thevenin's theorem or Norton's theorem. However I have read in some sources ...
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1answer
104 views

Confused on Calculating Resistance Distance Matrix

I am trying to create a computer program to compute the equivalent resistance over any points on any rectangular set of resistors (all with a resistance of 1 ohm). It seems that the resistance ...
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votes
1answer
89 views

Differentiating a sinusoid [closed]

http://i.stack.imgur.com/ndLgm.png I don't see the how the author derived that $\frac { dv }{ dt } \leftrightarrow\overrightarrow { V } j\omega$.
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2answers
2k views

How can a circuit function with two negative battery terminals facing each other?

Here is a drawing of the circuit that is confusing me: I don't quite understand how batteries work in this diagram. If a battery has a negative and positive terminal, there must be a barrier ...
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5answers
5k 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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1answer
316 views

Electromotive Force Definition for Induced Current

If in DC , Emf is the work done to carry a unit positive charge from -ve to +ve terminal . What is induced EMF then , in a similar sense ? To carry a unit charge around a loop once along a fixed ...
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2answers
2k views

Frequency Response RLC circuit - Current against Frequency graph - Symmetry?

I understand that in a Frequency Response experiment dealing with an RLC circuit, the graph of Current against Frequency is supposed to be symmetrical about the resonant frequency theoretically. ...
5
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2answers
650 views

Why does a capacitor discharge?

Suppose a charged capacitor (parallel plates), the negative and positive charges on two plates attract each other. Which force cause the negative charge carriers (electrons) move through the circuit ...
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1answer
86 views

Can someone explain this intuitively please?

In a static situation we defined voltage as energy/unit charge, or j/c. As the distance between the charged particles increased, the voltage decreased. Now why do we not apply this in a simple DC ...
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0answers
135 views

Transfer functions of active filters

I've been looking for some straightforward method or trick to obtain the transfer functions of active filters (like the Sallen-Key filter, the butterworth or Cauer topology etc...) since KCL or KVL ...
0
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2answers
429 views

Out of phase voltage current source and resulting power

Examining the following graph, I am trying to understand the power plot. The power appears to take on a negative value when the current changes direction or the voltage changes polarity. Negative ...
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3answers
2k views

Path of an electron through an electric circuit

When a potential difference is applied across a conductor, and if an electron moves from the negative terminal of the battery and reaches the positive terminal, then I want to know if the electron ...
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3answers
3k views

How exactly does a resistance reduce current?

I've heard that resistors are used to decrease current to a particular appliance, such as in the regulator of a fan. However, I've also heard that the total current in a circuit is always the same- in ...
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1answer
166 views

Full wave rectification [duplicate]

In the construction of a full wave rectifier, why is there central tapping in the secondary winding of the power transformer? What's the pure reason behind it? If there was no central tapping, what ...
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3answers
207 views

Electronic filter

Can you explain, please, step-by-step how an electronic filter does work? For example, high pass filter. I know It's a trivial things, but I can't get it completely. Don't bring me formula and etc. ...
2
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1answer
155 views

Am I properly identifying the resistor terminal voltage?

The frequency applied to a circuit of voltage 120 V with a real coil and a resistor has a value of 50 Hz. The resistance of the resistor is 10 $\Omega$. The voltage at the resistor terminals ...
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2answers
327 views

Why the CFL light bulb flashes even if there is a power cut?

Today when there was a power cut I saw that the CFL light bulbs were flashing time to time at regular interval. I was amazed as there was no source of power to the CFL bulbs even they were flashing as ...
3
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6answers
9k views

Parallel circuits - Overall resistance decreases with additional resistor [closed]

Let's say that there is a parallel circuit with two identical resistors in parallel with each other. If a third resistor, identical to the other two, is added in parallel with the first two, the ...
3
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2answers
1k views

Round bulb and Long bulb in Series Circuit

If you have a series circuit with a battery, one round bulb (with thicker filament), and one long bulb (with thinner filament), the round bulb does not light up and only the long bulb lights up. ...
3
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3answers
4k views

Capacitor circuits with light bulb

Let's say we have a normal circuit with a light bulb, with wires and a battery. When one places a capacitor in this circuit, how is the light bulb able to light up, even when the capacitor prevents ...
0
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1answer
10k views

What is the role of center-tapping in a full wave rectifier?

Note: I have already tried googling. Although similar questions have been asked on different forums, I couldn't find a detailed explanation, which I could really understand. Circuit diagram ...
0
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1answer
2k views

Relationship between resistance and voltage drop

In a series or parallel circuit, if two bulbs have the same resistance, do they have the same voltage drops? The problem I am asking about is below. Do A, B, and C have the same voltage drops since ...
0
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1answer
239 views

a metal bar on a pair of conducting rails that carries a current

This is a homework question, and I solved it already, but something bugs me. So the problem is stated as following: A metal bar of mass M sits on a pair of long horizontal conducting rails separated ...
0
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1answer
284 views

Cable TV version of infinite ladder network [closed]

This is a problem in a college physics textbook, and its bugging me that I can't get it. The figure shows a circuit model for the transmission of an electrical signal, such as cable TV, to a large ...
0
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4answers
336 views

Why is there a potential difference?

The question then asks for the potential difference between $X$ and $Y$, which is claimed to be $3.6\text{ volts}%$. Why would there be a potential difference in this case? If I connect a lightbulb ...
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3answers
553 views

kirchhoff's law.Simple question [closed]

So far I calculated total resistance and it is 4.66 ohms and there is 12 volt voltage across them, what is the best way or HOW to calculate current for each resistor ?
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1answer
520 views

AC Circuit Theory Maximum Power Transfer

I am currently hitting a barrier with regards to the basics of this question. A 50HZ supply is connected to various given impedance's, calculate the maximum power transfer. Maximum power transfer I ...