3
votes
What happens inside a conducting wire if it is placed in an electric field?
If the field is static, the conductor will be equipotential in the equilibrium state. If you bring the conductor in the field from a region with no field or with a different value of the field there ...
- 6,345
3
votes
Why Does an Electric Field Arise In This Situation?
The problem lies in the measurement method, not in the medium itself. As soon as you connect the battery, you will always have an electric field (actually also if you do not connect the battery), no ...
- 7,104
2
votes
Why Does an Electric Field Arise In This Situation?
Water conducts electricity, so the battery drives a steady current through the water. There is therefore a current desity
$$
{\bf j}= \sigma {\bf E}= - \sigma \nabla \phi$
$$
where $\sigma$ is the ...
- 41.3k
2
votes
How to understand the model of electric current and potential in circuits?
It is not the electrons themselves that carry the energy in the circuit. They do not gain any energy overall in the battery, and nor do they lose any in the resistor, overall.
The electrons undergo ...
- 56
2
votes
Voltmeter reading in a bridge circuit
Instead of presenting a solution, I'd like to point out where you're going the wrong way.
You're talking about "the" resistance and "the" current, as if there were only one ...
- 2,048
2
votes
Electric Circuits and Kirchhoff's Voltage Law
Voltage, in the sense of potential difference (potential drop when going from $a$ to $b$) $\varphi_a - \varphi_b$, can be expressed as integral of the conservative part of electric field:
$$
\varphi_a ...
- 27.9k
1
vote
Accepted
Current without potential difference, in the given circuit?
There’s no revelation here. All you have established is the voltage drop across the 3 Ohm resistor equals the voltage rise across the 1.5 volt battery. You get the same result if you start at A and go ...
- 55.6k
1
vote
Current without potential difference, in the given circuit?
potential difference across point A and B is zero, but still a current is flowing (in the circuit) thought it! How?!
Clearly the battery is providing the necessary EMF for the current.
The idea that ...
- 64.4k
1
vote
Voltage and electric field in a closed circuit confusion
It seems intuitive to think that to keep the electrons moving, the electric field must act everywhere in the circuit (1).
You have to realize this intuition is like the intuition that in order for ...
- 27.9k
1
vote
Voltage and electric field in a closed circuit confusion
What is wrong here?
You aren't thinking about what the "ideal wire" model is simplifying.
The real wire has a small resistance. Maybe a few milliohms. And so there is a small electric field ...
- 22.8k
1
vote
Accepted
Energy stored in capacitor over time
The correct answer would be a quarter. It is very much like the energy stored in a spring is
$$E = \frac{kx^2}{2}$$
Electrons repel each other. If you add electrons to a metal, the metal is charged. ...
- 25.6k
1
vote
Will a surface perpendicular to the electric field always be equipotential
In the case of electrostatic fields indeed equipotential surfaces are perpendicular to the electric field. In other cases the vector potential should also be considered.
- 21.7k
1
vote
Accepted
How to find the potential difference between two charged spheres?
If $a - b = c$ then it implies $b-a = -c$ so both of your propositions are equivalently correct.
- 548
1
vote
Accepted
$V$-$I$ characteristics and circuits
The slope of the $I\ \text{against}\ V$ curve gives the reciprocal of the so-called 'slope resistance', $\frac{dV}{dI}$. This can be a useful concept, but it's not relevant here.
Here are some hints ...
- 27.9k
1
vote
Confusion about electrical potential difference
I'm not sure if I understand your question correctly, however I assume your talking about the potential difference across each of the 2 distinct paths being constant. You can think of it as "...
- 3,740
1
vote
Accepted
Confusion about electrical potential difference
The energy loss of a specific charge (like an electron) on passing through a resistor depends not on the resistance, but on the voltage difference. That voltage difference itself depends on the ...
- 33.7k
1
vote
Voltage and series circuit
In a series circuit, the voltages are different when the resistances are different If $U$ is the total voltage across both resistances, the drop over the fist one will be $U_1=\frac{R_1}{R_1+R_2 } U$ ...
- 1,157
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