# Questions tagged [short-circuits]

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### 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 ...
1 vote
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### 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 ...
69 views

### 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: \begin{equation} U |u_0\rangle = \frac{1}{\sqrt{12}} \begin{pmatrix} |3\rangle +...
173 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? ...
61 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 ...
115 views

### 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 ...
260 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 ...
31 views

### 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 ...
1 vote
80 views

### 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
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### 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
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### Why doesn't Kirchhoff's Law work when a battery is shorted with an ideal wire?

Kirchhoff's law states that the sum of voltages around any closed loop sum to zero. The law is true as the electric field is conservative in circuits. Why can we not apply the law here? Why doesn't ...
71 views

### What's the source of voltage? [duplicate]

I've been told that in a DC circuit with a battery the negative terminal of the battery "pushes" electrons in nearby atom away of it and those by themselves cause electrons in other atoms to move, but ...
91 views

### Is there a non-zero field within an ideal current carrying wire?

Its true that there is a non zero field (in fact,a field of the magnitude of counter electric field inside the battery used) within a current carrying IDEAL wire (unlike static condition). Thus there ...
160 views

Why the red wire generete a short-circuited with $I_2=0$ and $\Delta V_2=0$? I have three loops and if I apply the 2nd Kirchhoff's rule, I will have $$\sum_{\color{red}{\text{2nd loop}}} \Delta V=0... 0 votes 1 answer 31 views ### Why do we leave out this 20 ohm resistor when tabulating the Thevenin resistance? Is it because of short circuit? [closed] I bumped into this particular question. I approached the question in the wrong way. I took into consideration of the extra 20 ohm resistor. but the answer key doesn't seem to consider that. Is it ... 2 votes 0 answers 615 views ### Why does this magnetic charger cause short circuit when it sticks to the metal leg of my table? [closed] Recently, I have bought this product. It is basically a USB cable, with a magnetic end, and a tiny attachment that goes into the mobile device. I plugged it into my laptop cooling stand (which has ... 2 votes 2 answers 533 views ### How could an ideal conductor with 0 resistance conduct electricity? [duplicate] A very simple circuit consist of a resistor, a battery, and some conducting wires connecting the resistor to the battery(assuming resistance of the conducting wire is 0). It is always assumed that ... 0 votes 1 answer 56 views ### Why is the information of a time delay missing in formulae of voltage drop across elements when we emulate DC with an AC voltage supply? In an AC circuit, the reactance of capacitive and inductive elements are determined by the frequency of the AC signal. When we try to emulate DC analysis by putting \omega = 0 , the capacitive ... 1 vote 3 answers 243 views ### Would we need a battery if there was no resistance? I'm struggling to wrap my head around this idea. Imagine that we have a wire with no resistance (R=0). According to Ohm's law V=IR, the voltage drop (V) between any two points would be 0, and ... 5 votes 5 answers 2k views ### Resistors parallel to short circuit I have a trouble solving this problem. (Actually, each resistor is not parallel with the bottom wire since the voltage across each of them is different with that of wire.) In the manual, the bottom ... 0 votes 2 answers 51 views ### What will happen if an ideal current source is connected to a isolated resistance? I know that ideal current source is a theoretical thing. But when it comes to solve problems we have to consider these scenarios. Now suppose an ideal current source is connected with an isolated ... 1 vote 2 answers 3k views ### How does current flow in a short circuit? [duplicate] In a short circuit, the potential difference across the terminals of a battery (consider a single cell with internal resistance)is 0 according to the equation$$V=E-Ir, where $r$ is internal ...
1 vote
There is this simple test: Three identical bulbs are connected in the circuit illustrated in the figure. When switch $S$ is closed: a] The brightness of $A$ and $B$ remains the same, while $C$ goes ...