Questions tagged [electric-circuits]

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

Filter by
Sorted by
Tagged with
1 vote
1 answer
11 views

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 ...
user avatar
1 vote
1 answer
26 views

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" ...
user avatar
0 votes
1 answer
26 views

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 ...
user avatar
0 votes
2 answers
28 views

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 ...
user avatar
0 votes
1 answer
71 views

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 ...
user avatar
  • 177
1 vote
1 answer
36 views

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'...
user avatar
1 vote
2 answers
56 views

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.
user avatar
1 vote
0 answers
37 views

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 ...
user avatar
1 vote
2 answers
49 views

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 ...
user avatar
0 votes
2 answers
54 views

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 ...
user avatar
0 votes
0 answers
20 views

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 ...
user avatar
2 votes
2 answers
73 views

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 ...
user avatar
  • 569
0 votes
1 answer
30 views

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 ...
user avatar
  • 3
-1 votes
0 answers
13 views

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
user avatar
0 votes
0 answers
17 views

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
user avatar
0 votes
0 answers
24 views

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 ...
user avatar
  • 569
0 votes
2 answers
44 views

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 ...
user avatar
  • 137
0 votes
1 answer
28 views

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 ...
user avatar
-2 votes
0 answers
19 views

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 ...
user avatar
0 votes
0 answers
18 views

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,...
user avatar
  • 1
-1 votes
1 answer
49 views

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 ...
user avatar
  • 101
0 votes
0 answers
11 views

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 ...
user avatar
  • 1
1 vote
1 answer
41 views

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}{...
user avatar
  • 113
0 votes
2 answers
18 views

What is the difference between the self-inductance of a branch and self-inductance of a loop in lumped circuit models?

When we talk about lumped circuit model, I get confused about the terminology that is generally used. For a loop, we do know that the total flux through the loop can be written as $\Phi = \Phi_{ext} + ...
user avatar
  • 970
1 vote
0 answers
32 views

Modeling the Effect of Magnetic Induction on Single Neurons

In this paper, the authors suggest a potential mechanism for magnetoreception in birds: as the Earth's magnetic field (taken to be homogeneous over sufficiently small spatial scales) passes through ...
user avatar
  • 339
0 votes
3 answers
36 views

Voltage and electric field in a closed circuit confusion

I have a doubt about the intuition behind Electric field and Potential difference. Let's imagine a closed circuit with a battery, a resistance and a lightbulb. We observe that the lightbulb is on. ...
user avatar
  • 260
0 votes
2 answers
71 views

How is there current if there's no voltage?

Hi, I was trying to solve this problem, it asks to find the reading of ammeter. I think it has no resistance here. Does it mean that there's no potential difference, no voltage across ammeter? But how ...
user avatar
  • 13
0 votes
2 answers
51 views

How to understand the model of electric current and potential in circuits?

According to what I have learnt, there is always a potential difference across a resistor in a circuit (having a battery). Considering a simple 'resistor' circuit, when we apply an e.m.f in the ...
user avatar
2 votes
2 answers
388 views

I’m trying to charge a capacitor. Would a bridge rectifier charge it like a battery would?

Since a bridge rectifier converts ac to dc. Will this charge my capacitor to max capacity how hooking it up to a battery would? The positive is charging the anode, while the cathode is grounded. Any ...
user avatar
0 votes
2 answers
33 views

If one of the parallels of a parallel combination of resistors is broken, how will it affect the other parallels?

All these bulbs have equal resistance and the equivalent current is 6A. I want to know what will happen if bulb 3 is fused. All the sources I have came across say that the bulb 1 and bulb 2 will glow ...
user avatar
-1 votes
1 answer
37 views

How to calculate the total resistance of this complex circuit? [duplicate]

how do I calculate the resistance of the following complex circuit?
user avatar
0 votes
1 answer
52 views

Is it possible to convert static electricity into current electricity?

Generally, static electricity is created by friction between two or more different materials and it doesn't flow through a circuit. On the other hand, current electricity is the flow of electrons ...
user avatar
-1 votes
2 answers
49 views

LC circuit in spring system

We have a setup of a metal spring with a mass. This would oscillate nicely. Additionally, an inductor with a capacitor also oscillates nicely. If we were to combine these two setups, where the mass is ...
user avatar
  • 1
0 votes
1 answer
18 views

Lamp filaments in a circuit

My answer to this question was: "The brightness of each lamp would increase due to more voltage available to spread across the now 39 lamps (since one burns out)" This, however, is incorrect....
user avatar
0 votes
0 answers
26 views

What is the probability of pulses from 3 detectors (with known rates) coinciding?

I have three detectors giving output (on/off signals) with the following properties: Detector 1: pulse width = 40 ns, pulse rate = 1 kHz Detector 2: pulse width = 40 ns, pulse rate = 1 MHz Detector 3:...
user avatar
0 votes
1 answer
39 views

Current flowing from lower to higher potential

In the above circuit, two cells are connected in series to an external resistance $R$. Now the current going from point $A$ must return back to point $B$ of the cell. But for that it has to pass ...
user avatar
  • 569
0 votes
2 answers
69 views

The Resistance in an electric kettle [closed]

I have an electric kettle with two parallel heating elements, both with resistance $R_0=2\,\Omega $. Both can be independently shut on and off. There is also another resistor with resistance $R$. Upon ...
user avatar
  • 11
1 vote
3 answers
133 views

Is an open circuit completely dead?

Probably the answer should be yes, it's like there would be no electricity source at all. But when I ask what's happening after a switch is turned on, I get the answer that the electricity then goes ...
user avatar
0 votes
1 answer
28 views

Why isnt the angle between EMF and LC impedance 90 degrees in AC circuit?

I have a generic LC circuit where the inductor and capacitor are in series and we have alternating EMF. I'm trying to find the the impedance of the circuit with phasors. A phasor diagram shows ...
user avatar
  • 31
0 votes
2 answers
43 views

Voltmeter reading in a bridge circuit

Why would it be wrong to calculate the voltmeter reading in the following diagram as one plus 2 ohms is 2/3 ohms as they are in parallel, hence the p.d. reading on the voltmeter must be the current ...
user avatar
-1 votes
0 answers
14 views

Exercise with full wave bridge rectifier [migrated]

I study an example of youtube video https://www.youtube.com/watch?v=Kl8IOESVWlM an i want to make transfer function vo = f(vi) when i use the piecewise linear diode model. I worked with the following ...
user avatar
0 votes
1 answer
29 views

Why can't we use a slip ring instead of a split ring in a dc motor?

I've been taught that in a dc electric motor a split ring is used to connect the two ends of the rotating coil to two carbon brushes so that The wire does not get twisted and The current passing ...
user avatar
  • 95
2 votes
3 answers
89 views

Possibility of current flowing through this circuit [closed]

I am having some problems in solving this circuit. I will share my ideas here. Please correct my steps which are incorrect. We emit current only from battery $V_1$ and let that current be $I$. 2)Now ...
user avatar
  • 569
0 votes
2 answers
52 views

Can we make electron drift velocity faster than light by reducing area of resistor?

We know that $I= nqAV_d$. Can we send high current ($I$) through a "fat wire" (more $A$) then reduce $A$ at the resistor so much that $V_d$ becomes faster than light in order to maintain $I$?...
user avatar
0 votes
0 answers
23 views

Electric flux in inductor

An AC circuit is set as follows The circuit consists of a voltage source, an ideal inductor with inductance $L$ and a ideal capacitor with capacitance $C$. The current through the circuit is $i(t)= ...
user avatar
0 votes
0 answers
9 views

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 ...
user avatar
0 votes
1 answer
23 views

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 ...
user avatar
-1 votes
2 answers
54 views

$V$-$I$ 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? ...
user avatar
  • 720
0 votes
3 answers
42 views

Inductance in AC circuit

Why does an inductor oppose a change in current and not voltage? Is it a rule or is it because of lenz's law? Because intuitively the back e.m.f which opposes a change in current should also oppose a ...
user avatar
  • 97
0 votes
1 answer
22 views

Voltage and series circuit [duplicate]

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 ...
user avatar

1
2 3 4 5
80