30 votes
Accepted

How will the current flow in the figure drawn below?

An approximate numerically calculated figure is attached. The figure is a two-dimensional result. Although 3D calculations is possible, the figure is easier to see in 2D. $\phi$ is potential in volts. ...
user avatar
  • 496
6 votes
Accepted

Example of information travelling faster than the speed of light?

Therefore, we can use the law of Biot-Savart No, you cannot use the Biot Savart law in this situation. The Biot Savart law is derived from the magnetostatic assumption. That is, the assumption that $...
user avatar
  • 65.8k
6 votes
Accepted

How to calculate the total resistance of the 5-cell (4 dimensional pyramid)?

In the article: Severino V. Gervacio, "Resistance distance in complete $n$-partite graphs", Disc. App. Math. 203, pp. 53–61 the author cites the surprising and elegant result (see refs. [3,...
user avatar
6 votes

How does current flow in a purely inductive circuit if the net voltage is zero?

How does current flow in a purely inductive circuit if the net voltage is zero? The problem in this question is that it is based on a completely wrong assumption. This concept of “net voltage” isn’t ...
user avatar
  • 65.8k
5 votes

How will the current flow in the figure drawn below?

Yes. There won't be any noticeable amount current at the ends of the rod because the electric field formed inside the conductor will be restricted so the electrons will dominantly experience the force ...
user avatar
4 votes

How does current flow in a purely inductive circuit if the net voltage is zero?

When the source voltage is suddenly made zero then the current will be decreasing at some rate and if an ideal inductor is present in a circuit then that decaying current will cause the magnetic flux ...
user avatar
4 votes
Accepted

Quantum Computing is not Analog Computing. Really?

Quantum computers are like classical analog computers in that they have a continuous state space, and are like classical digital computers in that they have a discrete output space. Anything beyond ...
user avatar
  • 17.5k
3 votes

Quantum Computing is not Analog Computing. Really?

Quantum computing is a form of digital not analog computing. I will explain why. First, let's note that the fact that the physical state space is continuous is not the relevant fact. For the physical ...
user avatar
3 votes

Why are computers much smaller than they are fast?

For a wire, a vast number of electrons are present. They barely move. Each electron only needs to move slightly to play its part in guiding the electromagnetic field along the wire. The signal ...
user avatar
  • 4,121
3 votes

Why does an electric field "concentrate" along a wire?

This is indeed something that seems rather mysterious at first. It is well known in the literature, but is often not discussed in a typical EE curriculum. It seems like the physics classes don’t think ...
user avatar
  • 65.8k
3 votes

Does current flow inside a battery?

Yes. When a battery is operating normally then current flows inside the battery from the negative terminal to the positive terminal.
user avatar
  • 65.8k
2 votes
Accepted

Why is it safe to touch a Van Der Graaf Generator?

Why is it safe to touch a Van Der Graaf Generator? If by "safe" you mean not causing ventricular fibrillation, then it's because the energy of the capacitive discharge is not sufficient to ...
user avatar
  • 56.1k
2 votes
Accepted

Cant understand why $C_1$ and $C_1$ are in parallel?

The two C1's are not in series, for exactly the reason you say. However, because C1 is equal to C1 and C2 is equal to C2, we can show by symmetry that, assuming we start with all capacitors discharged,...
user avatar
2 votes

How does current flow in a purely inductive circuit if the net voltage is zero?

If we're talking about a purely inductive circuit, the induced emf is equal and opposite to applied emf. Isn't it just like two identical batteries in opposition? If that's the case, how does the ...
user avatar
2 votes

Why are computers much smaller than they are fast?

Someone else with more knowledge can correct me, but I think it might have to due with either the capacitive effect or the field effect in circuits. 1) electrical components often have some capacitive ...
user avatar
2 votes

Induced e.m.f and induced current in a Electro Magnet during Electro Magnetic Induction

1 My question is, . . . . . . , the induced current will be developed in the 1st wound,and it will reduce the actual current heavily, so when the current will reach the 2nd wound, . . . . . . so ...
user avatar
  • 77.9k
2 votes

What happens to a non-conductive material in a circuit?

An electric fence works by having an open circuit in normal conditions, and then only having a closed circuit when an animal touches the fence. So the end of the wire is not particularly problematic ...
user avatar
  • 65.8k
1 vote

Electricity Paradox

In a static situation, zero resistance implies no potential difference. The current keeps flowing through the branch without resistance even after the source for initiate the current is not more ...
user avatar
1 vote

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

[...] What stops the the current from flowing thought the resistor? Well, the resistance stops it. Every charge that reaches the junction will move in the direction of least resistance. They will ...
user avatar
  • 46.6k
1 vote

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

Suppose there is 1 A flowing through the zero-resistance wire. What then is the voltage across the wire? From Ohm's law we know the voltage across it is 0 V. Since the other resistor is in parallel, ...
user avatar
1 vote

What is the correct definition of EMF in a circuit?

What is the correct definition of emf in a circuit? Neither of the equations you wrote is the definition that Griffiths provided for EMF. His definition of EMF is in Eq. 7.9 of the reference you ...
user avatar
  • 7,614
1 vote

The misconceived difference between the electrostatic and electric force

(It's a good idea to provide specific references, rather than some vague "source".) The electric force is $\vec F_{elec}=q\vec E$. Such a force can be called "electrostatic" the ...
user avatar
  • 8,677
1 vote

Induced emf by a single wound coil

The induced emf depends on the rate 0f change of current not the value of the current itself and it can never "win" in the sense of stopping the current completely because it id does then ...
user avatar
  • 77.9k
1 vote

Why are computers much smaller than they are fast?

In CMOS every input to a transistor or gate is driven by a precious CMOS output. So in all cases you end up with a rather high source impedance R (say 10 kOhm) driving a capacitive input C (say 1 fF). ...
user avatar
  • 730
1 vote
Accepted

Showing that its always possible to convert the circuit into the below equivalent form

Well at the end of the day if electricity flow is coming in let's say by A and going out by B and C, you will have some proportion of how much goes through B and how much through C and that will give ...
user avatar
  • 551
1 vote

How does current flow in a purely inductive circuit if the net voltage is zero?

There is a perfect mechanical analogy. If we push an idle car in a flat ground, we feel a force $$F = -m\frac{dv}{dt}$$ where $m$ is the mass of the car and $v$ its velocity. Of course, at $t=0$, the ...
user avatar
1 vote

Find the EMF of the source in the circuit

The question doesn't tell you WHERE the work is to be done. To get the answer given for the emf, you have to assume that the 1000 J is the total work done in the circuit, that is the sum of the work ...
user avatar
  • 28.1k
1 vote
Accepted

Why don't we know the electric potential at any point in a circuit, only the difference in the electric potential (voltage)?

In loop analysis where we apply Kirchhoff's voltage law (the algebraic sum of the potential differences around a loop equals zero) it is only necessary to consider potential differences. In doing node ...
user avatar
  • 56.1k
1 vote
Accepted

How does a capacitor discharge through another capacitor and resistor?

The resistance determines how fast the charge will transfer from one capacitor to the the othr. The final state is determined by the equality of the potential diference across the two capacitors. The ...
user avatar
  • 6,568
1 vote
Accepted

What would be the shape of the magnetic field around a current carrying wire made up from iron?

With the relative permeability $μ_{r}$ of copper at ~0.999 (diamagnetic) and aluminum as well as air at ~1 and for pure iron (99.8%) about ~5000 (https://www.engineeringtoolbox.com/permeability-d_1923....
user avatar
  • 3,202

Only top scored, non community-wiki answers of a minimum length are eligible