# Questions tagged [short-circuits]

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### Zero Shunt Resistance in Ammeter

To reduce the resistance of ammeter, we attach a shunt resistance in parallel to the galvanometer. Also, this allows galvanometer to measure larger currents even though it has less value of the full ...
116 views

### How would you find the equivalent resistance of these circuit diagrams given a wire with no resistor?

I understand how to combine resistors to find their equivalent resistance, but I am completely oblivious as to how to remove resistors that are shorted. For example, in the first image, there is a ...
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### Why There's No Current Flowing in This Part of The Circuit?

One time, in my Physic Class my professor ask us, "How much current is flowing in this circuit?" and everyone answer $5$ Ampere (Because, it looks like the resistor is arrange in the series ...
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### Is there any current flow from a battery to the earth?

Suppose I connect the + (or -) pole of a battery to the earth with a conducting wire, will there be a current flow? As I understand, the Earth is considered to be "neutral" in the sense that ...
171 views

### Short circuit vs circuit with load

I'm studying about short circuit phenomenal. From the information I have searched, given a small battery (AAA), if we connect the 2 poles of the battery directly with a wire, without load (i.e. the ...
146 views

### How would current be distributed among two parallel paths of zero resistance?

In an ideal circuit with two wires in parallel, if one path has zero resistance and another has a nonzero resistance, all of the charges will flow through the wire with zero resistance (if I ...
1 vote
72 views

### Mismatching Batteries of Different Voltages

Consider connecting two batteries of different voltages $x$ and $y$ in parallel. Considering a series circuit, the total voltage would be $x+y$. However what happens in this parallel case? From my ...
131 views

### How exactly does an inductor behave in a circuit after reaching its steady state?

I was solving this question in my coursebook and was not able to understand it conceptually. Though I did understand the mathematical approach to it. Now I understand that when the rod is given an ...
1k views

### Why does a short circuit occur? [duplicate]

For example, if you have a battery and you connect both ends with a short circuit with zero or low resistance, why does it short circuit? What causes this internally? What are really happening with ...
38 views

### Doubt about short circuit [duplicate]

I have been asked to find the equivalent resistance in the following circuit. However, is the circuit valid, as a zero resistance wire is connected between 2 different potentials? Also, how to ...
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### Are short circuits a type of parallel circuit?

Since short circuits have >1 electrical pathways for current to flow, the unintended and intended pathway, I would assume that short circuits are parallel circuits and therefore current is ...
1 vote
204 views

### Short circuit doubt [duplicate]

Short circuits occur when a live wire comes in contact with a neutral wire due to poor insulation and stuff, and the main gist of this word short circuit is the fact that the wire gets heated up so ...
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1 vote
38 views

### Short circuit on one branch of parallel connection [closed]

I don't understand how that extra branch that starts in (a) affects the circuit. If R4 did not exist, then r2 and r3 would be ignored but now you have to take into account the (b) knot. How can we ...
81 views

### Why short circuit doesn't takes places in a homopolar motor?

In a homopolar motor we directly connect copper wire to a battery without any resistance with a magnet in bottom, so why doesn't a short circuit takes place?
133 views

### KVL in short circuit with 0 resistance [duplicate]

According to KVL, $\sum \epsilon = \sum RI$ in any closed loop. However, in an ideal circuit with no resistance, R is $0$, and hence $\epsilon$ must also be $0$. Does KVL not apply in this case?
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1 vote
2k views

### How does earthing a conductor make its potential zero?

My teacher explained about the earthing of a conductor. She said that when we connect a conductor with the Earth, its potential goes to zero because the Earth always has zero potential; however, she ...
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Imagine that you has a large electric potential difference across two parallel branch's in a circuit. One branch has zero electric resistance, and the other branch has a load such as resistor. Which ...
675 views

### Why dose current only take the path of zero resistance in a parallel circuit?

If a resistor in placed in parallel with a wire of zero resistance the current only flows though the path of zero resistance. What stops the the current from flowing thought the resistor? Also how do ...
506 views

### Will I get a shock holding a superconductive wire?

Assume a current carrying superconductive wire is in front of me, with no voltage source attached. If I hold it, will I get a shock? Forget for a minute that the superconducting wire will be too cold ...
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1 vote
180 views

### A simple question about parallel connecting a short circuit (+the physical interpretation)

1. Introduction We know that $$1/R_1 + 1/R_2 = 1/R_t \ (equation \ 1)$$ $$\therefore R_t = \frac{R_1\times R_2}{R_1+R_2} \ (equation \ 2)$$ when $R_1$ and $R_2$ are connected in parallel and $R_t$ is ...
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### What does it mean to ground in this context?

This is a homework problem that I already submitted, but am still unsure about. I am consider the following situation, re we have a conducting sphere of radius $R$ with charge $q$, which is surrounded ...
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### Is the eigenvalue of an eigenstate the same as its (global) phase?

I'm trying to understand Shor's Algorithm by reading this Qiskit textbook. At some part the following equation comes up: U |u_0\rangle = \frac{1}{\sqrt{12}} \begin{pmatrix} |3\rangle +...
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2k views

### Why can you shortcircuit a car battery with a wrench in your hand and stay safe?

In this demonstration by Prof. Walter Lewin a car battery is shortcircuited with a wrench. The experimenter is holding the wrench in its bare hands, so why he is not experiences an electric shock? ...
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1 vote
177 views

### Kirchhoff’s Voltage Law validity in short circuited circuit

Imagine a circuit with a battery and a resistor. Now I connect a resistance-less wire in parallel with the resistor. There will be a potential difference between the two ends of resistor, so current ...
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### A problem with the path of least resistance

I have a question about short circuits that I haven't been able to solve. From this we know: The total voltage V is constant, and the total current I is inversely proportional to the total resistance ...
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1k views

### Can grounding wrist prevent electrical shock?

Today while repairing some electronics and wearing anti-static wristband like on picture below I got thinking - in theory, would it be possible to avoid shock while working on mains by grounding ...
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### Magnetic rail problem with inductor and battery (resistance less)

A metallic rod (negligible resistance) can slide frictionlessly on two parallel metallic rails separated by a distance l in the presence of a perpendicular magnetic field (B). The ends of the rails ...
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### Earthing vs. grounding

In some websites they say there is a difference between Earthing and grounding but some of them say they don't. Is there any difference between "Earthing" and "grounding"?
1 vote
173 views

### Voltage - Current Relationship (IV graphs)

This is probably a really simple question but for some reason, I'm finding it difficult to grasp at an atomic level. My physics textbook has a statement that says: "As the voltage across a ...
1 vote
366 views

### What means "A grounded conductor has potential equal zero"?

When I have a force field $\boldsymbol{\vec{F}}$ it tells me how the momentum of the particle will change given in a position on space. When we talk about an electric field \$\boldsymbol{\vec{E}} = \...
1 vote
123 views

### How does an instantaneous current discharge occur when you connect a power strip to itself?

It is a light hearted joke that connecting a power strip to itself is a source of "infinite power". While this is obviously untrue, I always disregarded it and never really thought much of ...
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1 vote
460 views

### Why is the potential in conducting wire of negligible resistance is same as the potential of the terminal of the battery to which it is connected?

I am a high school student and I am very confused "why is the potential in conducting wire of negligible resistance is same as the potential of the terminal of the battery to which it is ...
264 views

### Is drift velocity of electrons 0 in 0 resistance wire?

In a 0 resistance wire, the electric field inside the wire is 0 as there is no potential difference. That means that when charges start to flow, no external force acts on them. But it doesn't mean ...
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1k views

### Calculating equivalent resistance [closed]

In the given circuit, find the equivalent resistance between points A and B. I solved this question in two different ways, out of which one gave the correct answer. The correct method is the most ...
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1 vote
2k views

### If there was zero potential difference between any two points in a circuit would current still flow? [duplicate]

Suppose there is a wire of zero resistance.So,by Ohms law it must have 0 potential difference between any two points across the resistor,now one connects the wire to a battery which has non-zero ...
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117 views

### Does random motion of electrons take place in 0-resistance wire?

In nodal analysis we often assume a wire to have 0 resistance and hence we assume that its ends have the same potential. As the potential difference across the ends of the wire is 0, there is no ...
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1k views

### Why do resistors in parallel with uncharged capacitors get eliminated from the circuit?

I was doing a problem where I was asked to find the current in an R-C circuit 'just after' the switch had been closed i.e at t = 0. All of the capacitors are initially uncharged. Could someone explain ...
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### Graph profile of the voltage drop vs resistance across a resistor, and the physics behind electric potential difference

I am a student and I have been trying to understand the relationship between voltage drop and resistance, and the underlying physics of Kirchhoff’s voltage law. I am aware of Ohm’s law and I can ...
1 vote
359 views

### What are the the actual similarities between Electric Circuits and magnetic circuits

I have surfed google to find an answer to that but all I keep seeing is "differences" and not actual similarities. So what exactly do electric circuits and magnetic circuits have in common.I ...
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### Can deadly electrocutions be prevented by wearing a simple wire?

One way to die when working with electricity is for enough current to pass through your heart, not much is needed. Often you are protected by wearing shoes or by the current flowing through two parts ...
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### Capacitors charging, resistance much more?

I am overwhelmed by the amount of doubts i am having regarding this device (CORRECT ME WHEREVER I AM WRONG PLEASE) First things first if we connect a capacitor using two ideal wires (for each plate) ...
715 views

### Direction of current using superposition method

I have to calculate the current I and the voltage between a and b using the superposition theorem. I can solve this directly by calculating the voltage between points, but I have to do it with that ...
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### Can someone explain, in clear terms (not unmathematical) what short circuit is? [closed]

I don't get the idea about what short circuit is. In a few questions I have come across, it appears to be a short circuit but the answers say otherwise. In fact, I don't have a conceptual ...
221 views

### Why would lamp A be shorted here in this circuit when testing the circuit with a power supply?

I'll really appreciate a response to this question, thanks for considering. Suppose I have this circuit (image from a CIE past paper question): Actual text (image here) in the problem: It is said ...
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### DC circuit- parallel vs short circuit [duplicate]

In a DC circuit, imagine a resistance of 10 Ohms connected parallel to a resistance of 20 Ohms, which is also parallel to a battery of V volts. In such a case, current will be distributed to the two ...
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1 vote
866 views

### Short circuiting a PN semiconductor device

Consider the potential distribution across a PN junction. The difference in the Fermi levels between the differently doped semiconductors leads to a 'built-in' voltage across the semiconductor ...
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### Why doesnt a wet circuit work

I mistakenly poured water on my the area of my TV remote which has the cell and apparently the circuit connections.A thing to ponder is that why doesnt a circuit work when it becomes wet , despite it ...
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### Root mean square current

An electric bulb is designed to operate at 12 volts DC. If this bulb is connected to an AC source and gives same brightness , what would be the peak voltage of the source? To this question answer is ...
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