# Questions tagged [electric-circuits]

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

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### How is surface charge induced on the surface of circuit wires when connected to a battery?

Understanding: I watched the newest Veritasium electricity video and he said that the electric field inside the wires of the circuit that causes the electric current to flow is created by both the ...
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1 vote
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### Do electric fences such as those typically used to fence cattle generate magnetic fields?

I'm using magnetometers near electric fences and I'm wondering if the electric fence should be detectable and if so, how close do I need to be to the fence for there to be a "measurable" ...
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### Why is current same even if the area of the conductor differs?

Current is directly proportional to area if area of conductor increase Current increases but in conductor like a horizontal frustum as area increases current remains same I have learned this equation ...
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### Instantaneous current and average current

Imagine a simple electrical circuit with a battery and resistor. We know that the average current in any part of this circuit remains same . My question is : is the instantaneous current also same ...
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### Is it solvable a circuit exercise like this?

Let's suppose we want to find $I_x$ e $V_y$ here $I_x=2\,$A is trivial, but book says $V_y=-4\,$V, Why? Is $V_y$ fixed if I don't know anything else about the elements of the circuit, except what is ...
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1 vote
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### Nickel gauge factor and why is it so quirky?

Hi so I've been researching the piezo-resistance effect and experimenting with finding different metals' gauge factors by applying stress on a wire and measuring the change in resistance however I can'...
1 vote
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### Why is lamp D off?

I understand the other lamps, but the answer for lamp d is that it is off as no current flows through it. I don't understand why? Please help.
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1 vote
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### By what medium is information about electric field propagation communicated?

After watching the recent Veritasium video on electricity, I, like many other people was skeptical. I got a 75m length of copper wire, and an oscilloscope, and ran the experiment myself. My results ...
1 vote
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### Why do we feel electrical shocks?

So electrical energy from source to device flows in the direction of the Poynting vector. My question is what do we feel exactly when we get an electrical shock? Before I learned about Poynting and ...
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### How do I determine which direction a current is travelling in a wire when it has two junctions?

For example in this circuit image, assuming the (DC) current starts from the battery and goes up, it then diverges at one junction and according to this junction, the current travels down the middle ...
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### DC Circuits: Has this question taken into account power dissipated due to cell's internal resistance? [closed]

See 3 question attachments and 1 mark scheme attachment. Question is taken from a UK spec. For part 4.3, the mark scheme says the electrical power supplied by the solar cell is equal to I^2 x ...
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### EMF being equal through KVL

In the given figure,we connect three cells of different emf which are $V_1,V_2,V_3$ with a resistance $R$ in the first loop. Now suppose we emit current $I$ from $V_1$. $I$ gets divided into $I_1$ and ...
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### Work done by battery [closed]

In charging a capacitor to a charge $Q$ Is there an equivalent to this in setting up current through an inductive circuit? Energy stored in inductor $= 1/2Li^2$ What would be the work done in setting ...
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### What will be the equivalent resistance of the circuit? [closed]

I am getting different answers 2 ohm when I used symmetric cutting method and 4/3 ohm when I used junction method
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### How do you determine current directions in a circuit with multiple voltage sources? [duplicate]

is there a method to determine the current directions for a circuit where there are multiple voltage sources? thanks
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### Diode in infinite circuit [closed]

This is an infinitely long circuit where the main voltage source is $V$ and other sources are $V_1,V_2\cdots$ where $V_n=n^2V_1$ for $n \ge 1$. All the diodes are ideal which means their resistance is ...
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### Analyzing electric circuit with capacitor, inductor and resistor

In my Calculus book, they state the following for this circuit (image above): $L \frac{dI}{dt} + RI + \frac{Q}{C} = E(t)$, where $E(t)$ is the electromotive force (also known as $\epsilon$), due to ...
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### Why is the electric field inside a conductor with charges laying on its surface zero? Is something wrong with my understanding of the concept?

We know that the electric field lines of a unit (point) charge is represented by drawing lines in all the directions radially outwards or inwards (depending on whether the charge is positive or ...
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### Electric circuits [closed]

I am having a trouble solving this question about Diodes and voltages, the thing is I have the following circuit that is shown in the image and I know that the input voltage Vi can be described using ...
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### Quantum nonlinear resonator/ transmon qubit

The transmon qubit -quantum non-linear resonator- has 4 elements in the electrical circuit. (Here is the circuit) starting at the 21:00 mark. We have R, L, C,Cd and Voltage. I already know which L,C,...
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### Why two wires are used in railway overhead equipment? [closed]

While watching the train video's I came across this overhead wires. After searching on internet I found that both catenary and contact wires carry same voltage and connected by vertical wires called ...
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### DC Bias Characteristic of Ceramic Capacitors under Transient

It's pretty well documented that many ceramic capacitors will "shed" capacitance with increasing DC bias. Seems that the mechanism is pretty well outlined too. (The physics behind DC voltage ...
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1 vote
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### Discharging two capacitors in series

I have two capacitors, C1 and C2 charged in series and I want to discharge them through a resistor. Does the discharge equation still hold here for each of the capacitor? For C1, Q_{1}=Qe^{\frac{-t}{...
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### Equivalent circuit for a lossy dielectric having non-zero volume charge density

So I was reading about the circuit diagram representation of a lossy dielectric, in which they considered that the dielectric had no charge in it. But suppose if a dielectric has a volume charge ...
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### What happens inside a conducting wire if it is placed in an electric field?

what happens when you place a long Finite conducting wire in an Electric Field , does current flow through it ? Is Potential Same all over the wire ? i just got these questions in my mind as i was ...
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### $V$-$I$ characteristics and circuits [closed]

The only solution stuck in my head goes through finding the resistance from the slope of the curves and using it somehow in the solution, however, I can't figure out what voltage do I use for X and Y? ...
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Suppose I have 2 series circuit. One will have resistance $R_1$ and the other $R_2$. Now my question is why is voltage difference same across both resistor? The top part of both resistors should have ...