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

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Question on an unbalanced Wheatstone bridge

Let, P/Q = R/S in the usual sense of a Wheatstone bridge where PQRS are resistances. Then we know that the potential between midpoints of PQ and RS are equal and there's no potential difference ...
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4answers
1k views

What is the difference between a circuit with a resistor and one without it in energy terms?

In Fundamentals of Physics (HRW), an equation is derived for the current in a circuit in terms of its emf and resistance by the 'Energy method'; that is, deriving $\epsilon = i \cdot r$ and saying ...
12
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4answers
3k views

Symmetry in resistor circuits

Given 6 points that are connected with each other with a resistor of resistance $R$, find the resistance between any two points. (Answer: $R/3$) (All the conducting wires have the same ...
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0answers
34 views

What is ultimate AC frequency and phenomena related to it?

Just as in title. What is the top AC frequency physically possible to obtain? And are there (and if yes, what?) phenomena occuring only at large frequencies? I'm thinking about a metallic wire. I know ...
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7answers
30k views

Power dissipated in series versus in parallel

Do two resistors in parallel dissipate more heat per unit time for an applied voltage when compared to two resistors in series?
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1answer
377 views

Circuit elements classification

I want to understand from theoretical point of view the structure of electric circuits. I don't mean Ohm's law or the Law of induction... E.g. there are resistors $R$, capacities $C$, inductors $L$ ...
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132 views

Calculating the output current and voltage of series and parallel connected solar panels

I have two solar panels, one is rated as $I=2A$ (current) and $V=20V$ (voltage) and the other as $I=3A$ and $V=15V$. If I connect them in parallel, how to calculate the current and voltage of the ...
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4answers
63 views

Many cells in parallel

If two or more cells of unequal voltages are connected in parallel (with the same terminal on the same side), is there a formula that gives the net potential difference? Also, by Kirchoff's loop law, ...
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0answers
56 views

Resistor and conductor and inductor

What I am gonna to have if: -an inductor is in parallel with a capacitor and all that group is in parallel with a resistor. I know that a capacitor in parallel with an inductor is: ...
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2answers
35 views

Time constant for this RC circuit

Well one problem boiled down to the following RC ciruit- $C_1$ was initially charged with $q_o$ and I thought after closing switch connecting $C_1$ and $C_2$ the maximum current discharging will be ...
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1answer
157 views

Does the electric field inside a circuit cause a potential drop with distance?

We know that when the system reaches steady-state(current does not change with time),the electric filed inside the circuit is constant. In many textbooks and lectures,professors make a graph like this ...
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1answer
34 views

Tesla Coil stops sparking until restart [closed]

I have a tesla coil with NT-1530-OUT Transformer, 23 turns (max) primary, 1m secondary(~1600turns), with MMC and rotary sparkgap. Gets 50cm sparks but try to tune the tesla coil by shifting top ...
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1k views

How can be the neutral wire at 0 volts when current flowing through it?

Voltage is potential difference, and current flows because of voltage. So if the voltage is zero, how can current flow through the neutral wire.
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2answers
214 views

Calculating the resistance of a 3D shape between two points

If I have an arbitrarily shaped object made of a uniform material of some specified resistivity, how would I go about calculating the resistance between two measurement points with known contact ...
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3answers
122 views

What happens to half of the energy in a circuit with a capacitor?

For a simple circuit with a battery supplying a voltage V to a capacitor, let us assume that the charge on the capacitor is Q. Now, the work done by the battery or the energy supplied is given by the ...
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2answers
353 views

Rate of flow of electrons in a simple circuit, given the current? [closed]

I have this question: The correct answer is C. I understand that the flow of electrons should be from Y to X because electrons flow opposite to "conventional current", which is from positive to ...
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2answers
353 views

Why is there no induced electric field in the experiment (Faraday's Law)

Below are three circuit diagrams for each of Faraday's experiments that allowed Faraday to come up with Faraday's Law. In Griffiths' Introduction to Electrodynamics Griffiths states (on page 302 of ...
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2answers
346 views

Why do high voltage transmission line workers need a Faraday cage suit?

In this video the high voltage transmission line workers are wearing a Faraday cage suit. Why is this needed? Without the Faraday cage, the resistance of the human would be very high compared to the ...
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1answer
52 views

Potential difference in a circuit of n cells = 0? How?

I was supposed to find the potential difference across any one cell in an arrangement consisting of n cells of EMF E connected in series in a closed circuit and internal resistance r. I proceeded by ...
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2answers
3k views

Resistor cube problem solving method

I was solving problems from Irodov when I came across the method called point of symmetry method. I cant find this method anywhere. So what is this method? Here is the link to the problem solution ...
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1answer
39 views

How will open-circuit voltage affect the Fermi Level Difference

The circumstances of my question consists of this: I have two materials, copper and cesium, and they are sandwiched together with a layer of cesium in the middle. It is connected only on a single side ...
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1answer
316 views

How does a bulb light up when it's connected in a circuit with an uncharged capacitor and a cell?

Since there is a capacitor, isn't it an incomplete circuit? How does the current flow across the dielectric medium? If a bulb was connected to a cell alone and if there was a break in the wires of the ...
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0answers
13 views

Current pass through different branch of network [duplicate]

How current knows that resistance in any branch of network is law show that more proportion of it pass through that branch?
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4answers
33k views

Why does connecting a battery's positive terminal to the negative terminal of another battery not create a short circuit?

This is a question regarding the physics behind the observation. I have guessed the answer to the question, but I may be wrong, so I want to wait for the responses before posting it. Some major ...
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1answer
7k views

short circuit an alkaline battery

i'm not doing anything related to physics, but i'm just curious : What really happen when i short circuit an alkaline battery ? some article in the net shown that fire/explosion can be happened when ...
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2answers
74 views

Why is this circuit component on without a potential difference?

From the following graph, determine whether (h) will be on or off: I think (h) should be off because there is no potential difference across it. Is this correct? Edit: Using the method provided ...
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1answer
295 views

Series / parallel capacitor network: find two capacitances and source voltage given some measured data

Capacitor 3 in Figure (a) is a variable capacitor; its capacitance $C_3$ can be varied. Figure (b) gives the electric potential $V_1$ across $C_1$ versus $C_3$. The horizontal scale is set by $C_3 = ...
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84 views

What is the strength of the magnetic field required to penetrate an average human body?

Introduction Suppose you are an experimental nanobot researcher trial-ling a new form of medication that involves activation and control of nanobots within the cells of the interior of the human body ...
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1answer
85 views

Transfer function of an RC circuit

I'm trying to reach the transfer function of an RC circuit which I am told is $$\frac {V_R} {V_\text{in}} = \frac{R}{\sqrt{(R^2 + \frac {1}{\omega^2 C^2})}} \cos(\omega t - \theta) \, .$$ Is this ...
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1answer
66 views

About the combination of two signals with capacitors

Here is a link of an article I've been reading. http://www.analoguehaven.com/moog/thereminblack/hotrod.pdf In page 4 there is a circuit schematic. Notice there is a part called variable pitch ...
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2answers
272 views

How long does it take for a capacitor to be fully charged if voltage is decreased? [closed]

Above is the picture of the circuit pertaining to this question. The question asked for the time it will take for the capacitor to get fully charged when the switch is in position B? So i guess the ...
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0answers
82 views

Does voltage depends on the charge present in an element?

Does the voltage depend on the charge present in a battery ? I know in capacitors q=cv. Hence charge present is proportional to voltage. Is it the same in the case of batteries?
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0answers
48 views

Approximate of self-inductance of a square wire coil

Imagine you have a square coil of wires with n turns. In order to calculate the self-inductance coefficient I should know the magnetic field. Is it acceptable to consider the 4 sides as infinitely ...
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1answer
1k views

Why are ammeters used in series and voltmeters in parallel?

As I'm reading a course on electricity, this one says that an ammeter should be branched inline and not on a bridge. Can someone explain to me physically why we branch a amperemeter inline and a ...
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2answers
3k views

Tying knots in power cables to prevent power surge from lightning strikes

There are plenty of references to this claim on the internet that tying knots in power cables will prevent a piece of equipment e.g. television or computer from a power surge. How can this be ...
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11answers
18k views

What is the difference between electric potential, potential difference (PD), voltage and electromotive force (EMF)?

This is a confused part ever since I started learning electricity. What is the difference between electric potential, potential difference (PD), voltage and electromotive force (EMF)? All of them have ...
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2answers
31 views

A circuit that is net charged

What differences would you measure if a circuit were significantly charged negatively? Would the resistance change? To be clear, I mean that excess electrons are added to the system. The circuit can ...
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3answers
133 views

Induction on a circuit with switch

I have the following circuit: It is subject to a steady, time-invariant magnetic field which points out of the paper. At $t = 0$, the switch closes. I thought that the magnetic flux would decrease ...
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2answers
44 views
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1answer
43 views

Will the current flow from the battery?

I am just trying to find out if the current enters into the positive terminal of the battery (if there is a battery with bigger emf ) will it get charged and charge will be stored and current will ...
2
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2answers
409 views

How to accurately mark with arrows an electric circuit

As I understood, we choose to mark the current with arrows going from the plus pole to the minus pole (even though we know that in reality it is the contrary). As I'm looking at electric circuits, I ...
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4answers
222 views

How does an inductor store magnetic energy?

I am trying to figure out what the potential energy of an inductor with a current really means. In a capacitor, the energy stored works like this: if you let the plates attract each other, before ...
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2answers
55 views

Doubt on resistor circuit [closed]

How are we able to flip the triangular resistor to the opposite breaking its connection with the lower 2r resistor?
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5answers
2k views

What causes contact resistance?

When two components are combined in an electric circuit, there is apart from their own resistances a contact resistance at their junction. This causes a sudden voltage drop of ...
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2answers
66 views

Why is voltage essential in circuits?

I understand what voltage is, but why is it necessary for an electric circuit to function? Why can't current flow without a voltage?
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0answers
32 views

What is the capacity of this circuit? [duplicate]

I simply can't figure out what the capacity of this circuit is. I can do the math myself, I just need a hint how to create an equivalent circuit where it is obvious what is parallel and what is in ...
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1answer
90 views

Highly inductive circuits question in general

I've been reading about self-inductance in circuits in M. Purcell's Electricity and Magnetism and came across an interesting fact: "What happens if we open the switch after the current $I0$ has been ...
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1answer
120 views

Electric Motors: why do they draw more current when stalled, and less when moving? [duplicate]

I'm familiar with how an electric motor works, and also familiar with what stall current and free current refers to in an electric motor. I'm also somehow familiar with the notions of energy being ...
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1answer
49 views

Does the power of the resistor change when the battery is changed?

Wanted to know whether the changing of a battery (potential difference)affects the change of power consumption of a resistor of a bulb. please tell me how the change will occur?
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1answer
144 views

Does the skin effect, eddy current / hysteresis losses contribute to Johnson noise in an inductor?

Based on my very basic understanding of the Johnson noise, it's not just a DC phenomena, but should change with frequency in a system, where there is a frequency dependent, real component to the ...