All Questions
54
questions
3
votes
6
answers
2k
views
Is electric current actually the flow of electrical charge?
In my high school, the definition of electrical current is "the flow of charges" but I have seen a video about how electricity actually works and it seems to me that electrical current is ...
0
votes
1
answer
42
views
Do electrons move faster towards the end of a circuit?
As 1 coulomb electrons go through 1 volt of potential difference, they gain 1 joule of energy. So in s series circuit, do electrons move faster towards the end of the circuit where they went though a ...
0
votes
0
answers
34
views
Is there electric field inside the conductor in moving charges case?
Is there an electric field inside a conductor when steady current passes through it ?
I have two conflicting notions here : I was watching this Electroboom video and at minute $14:00$ electroboom ...
2
votes
2
answers
127
views
Is it necessary for circuit to be closed in order for current to flow?
In case of earthing, we attach a single wire to the earth and if some residual electrons remain in the instrument they flow to the earth until the potential of the instrument also becomes Zero. So if ...
0
votes
0
answers
27
views
Can you measure different currents at different contact points for a volume of material made of two different metals with different conductivities?
My question is about the variation of conductivity in a volume of material and its effect on measured current. A volume is comprised of two metals joined symmetrically in a cuboid shape as in the ...
1
vote
2
answers
92
views
Energy conversions in Electric furnace
Heating furnaces use eddy current to work, but I have a problem understanding something, what are the energy conversions that happen in the electric furnace? Is it magnetic->electric->thermal or ...
0
votes
4
answers
84
views
About electric field and electric potential
We know that electric potential is the negative of work done by electric field in moving a unit charge from infinity to that place.
This statement shows that electric field causes a potential ...
0
votes
3
answers
1k
views
How does current actually flow in a wire?
When I was in my school I was taught that the electric field due to the battery is along the wire (from $A \rightarrow B \rightarrow C \rightarrow D $) and these are responsible for electrons at each ...
0
votes
1
answer
191
views
Motion of the electrons in a electric conductor when connected to a potential difference?
(I am a beginner in physics, so please forgive me if this is stupid.) Normally, under static electric state there is no resultant electric field existing inside a conducting material. But, when a ...
0
votes
1
answer
89
views
How Electric field is generated inside wire when a voltage source is connected to it? [closed]
I have found by my searches that the electric field inside wire is generated by the positive or negative charges accumulated at the surface of wire.
My question is, Why do charge get accumulated on ...
0
votes
1
answer
45
views
How does the electric field pattern looks like when current is moving inside the conductor and why this field is uniform?
We know that electric field is uniform inside a normal electric circuit consisting of some battery source and a conducting wire , $\mathrm{E}$ will be $\mathrm{E=V/d}$ , but I cannot think of a reason ...
0
votes
3
answers
100
views
What is the definition of direction of current?
Wikipedia defines the direction of current as:
The direction of conventional current is arbitrarily defined as the direction in which positive charges flow.
But suppose a region where there is a non-...
1
vote
1
answer
280
views
Does the number of electrons colliding in wire get double as the length of wire gets doubled?
Does the number of electrons colliding in a wire get doubled when length of wire is made twice with its area of cross-section remain constant.
My calculations for this are:-
For wire of length $L$ and ...
2
votes
2
answers
329
views
We know that $R={\rho l/A}$ but how do you define L and A, Area of cross section?
How do we define area of cross section of a conductor for resistance of a metal piece.
When you a wire which is generally cylindrical you have a length of it. Its area of cross section is a circle ...
1
vote
1
answer
24
views
In applications where heating is not the required from of energy, current is to be kept low as per Joules law. What energy is considered useful?
As per this paragraph from Wikipedia
"Joule heating is referred to as ohmic heating or resistive heating because of its relationship to Ohm's Law. It forms the basis for the large number of ...
9
votes
5
answers
4k
views
How does the speed of electricity become the same as the speed of light?
"The field due to the battery sets up a surface charge in the wire. The surface charge is negative near the negative pole of the battery, and positive near the positive terminal, and varies more ...
0
votes
1
answer
339
views
Why Electric field is same in a cross section of wire even if we change its thickness? [closed]
how does E remains same for the increased thickness. E is determined by field lines, if there is fixed number of field lines coming in then how it gets increased by increasing thickness of wire? To ...
0
votes
3
answers
343
views
On current enclosed by Ameprian loop
Ampère’s law is saying :
$$\oint \mathbf{B}\cdot \mathbf{dl} = \mu_{0}I_{inc} $$
Where $$I_{inc} = \int \mathbf J \cdot \mathbf {da} $$
But if my Amperian loop encloses a wire at an angle :
What is $...
-1
votes
1
answer
181
views
Electric arc and electric spark differences? [duplicate]
Why does an electric spark occur discontinuously while an electric arc is not extinguished as long as the current is maintained?
0
votes
1
answer
63
views
GENERATION OF CURRENT DUE TO ELECTRON FLOW
Why do flow of electrons generate current? whenever an electrons flows through a wire it generates electricity why does it actually happen?
0
votes
1
answer
80
views
How do charges away from the terminal react when the switch is flipped on?
Let us say we have a simple purely resistive DC circuit. When we flip the switch a current starts flowing which after some time becomes constant. Now, I know that the electric field across difference ...
0
votes
1
answer
85
views
Which electron moves first if you connected a wire to both ends of a battery at the exact same time?
Question 1:
Which electron in the circuit moves first if you were to connect a wire to both ends of a battery simultaneously?
Is it:
The last electron in the wire, which is pulled into the cathode of ...
1
vote
0
answers
92
views
Is magnetic field a consequence of electric field? [duplicate]
We know that magnetic field is produced by a current carrying wire with time varying current? My doubt is that- do the electrons in motion cause the magnetic field or is it due to some another reason?
0
votes
3
answers
1k
views
How does the battery create an electric field inside the conducting wire connected to its terminal?
In books, it is not explained exactly how the battery creates an electric field inside the wire. Also, is that the electric field inside the wire only or is it present outside the wire as well?
0
votes
2
answers
119
views
Can current flow through a capacitor submerged in electrolytes?
Imagine two flat conducting plates (3 x 3), one as the anode and the other as the cathode, submerged into electrolytes (e.g. sea water) and a DC current is applied to this apparatus. Could current ...
0
votes
1
answer
1k
views
Is the path of an electron between successive collisions (with positive ions of the metal)a straight line in the presence of electric field?
I feel that the answer should be yes. While the entire journey isn't straight, the journey between successive collisions is straight. But the internet and my book says the opposite (the path is curved)...
0
votes
0
answers
147
views
How do the electric field lines distribute inside a current carrying conductor?
We know that when we connect a conductor to a source of potential difference, an electric field is established inside the conductor. With the help of calculations which I show below, we can see that ...
0
votes
3
answers
561
views
Electric field and current
When we provide a potential difference in a circuit it does nothing more than provide an electric field to the conductor,When an electric field is provided in a conductor the free electrons move to ...
1
vote
2
answers
1k
views
Two charged spheres connected by a wire
I have a few doubts about this problem. So we have two charged spheres of radius $r_1$ and $r_2$, one is initially charged with a charge $Q$, while the other one is initially without charge. The ...
-1
votes
3
answers
120
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 ...
0
votes
2
answers
204
views
Do surfaces charge distribution in a wire move?
Upon reading matter and interactions ,In the chapter "electric field in a circuit" and surface charge distributions in a steady current, The book dosen't explain why doesn't the surface charges move ...
0
votes
2
answers
54
views
Current law explained
Kirchhoff's Current Law (KCL) is experimentally proven but what exactly happens?. I have made a model by taking the drude model and adding the interactions between the electrons and the reason why ...
0
votes
1
answer
76
views
Resistance and temperature relationship
When the temperature changes from $\theta_1$ to $\theta_2$, having $\alpha$, and the amount of resistance ($R_1$) in the previous temperature ($\theta_1$), we can calculate $R_2$, the amount of ...
0
votes
3
answers
133
views
Flow of charges inside a battery
I am having confusion about the flow of charges inside a battery which is connected to Circuit.
Question is, do charges move from one end to another through the battery? If yes, how? Do they move ...
1
vote
1
answer
1k
views
Two types of electric field
My textbook mentions that electric field produced by electric charge and that produced by changing magnetic field are different in nature.
After searching from various sources I found that electric ...
1
vote
1
answer
655
views
When DC current flows through salty water, how does the current flow? How can you tune the (narowness of) the path?
Consider this very simple and well-known experiment with dirty/salty water:
The light bulb turns on, and current is flowing. How can you know how this current is exactly flowing, and how the electric ...
1
vote
2
answers
153
views
Creation of electric field inside a conductor
My book says that as soon as the two ends of a conducting wire touches the two terminals of a battery, it generates an electric field inside the conductor. Why?
1
vote
1
answer
478
views
In the photoelectric effect experiment of stopping voltage, why isn't there a buildup of negative and positive charge on each side of the circuit?
Given this schematic, and that there is an electric field in the downwards direction due to the power supply, when the photon hits the emitter plate, the electrons leave the upper plate and hit the ...
1
vote
1
answer
7k
views
Why is the drift velocity directly proportional to the electric field?
If I double the electric field, that should double the acceleration of electrons inside the conductor in the general direction of the electric field. But why does that double the drift velocity, and ...
1
vote
2
answers
73
views
Current in a circuit
I know that to have a current in a circuit we need a potential difference that creates a gradient that makes electrons move from low potential to high potential. My question is that how, in a circuit, ...
1
vote
2
answers
1k
views
How does the electric field produced by a battery get transferred along a relatively long wire connecting the ends of the battery together?
My understanding of how the electric field produced by a battery gets transferred along the length of the wire is summarised in the following picture:
Is it correct to say that the force that the ...
0
votes
2
answers
800
views
Does the electric field strength along a simple circuit depend on the resistance of the conducting wire along its length?
A few hours ago I asked, if the electric field produced along and through a wire connected across the ends of a battery (a shorted out circuit) was uniform. The answer I was given was yes. But what if ...
0
votes
1
answer
84
views
how come electric field is o but current is there? [duplicate]
If electric field inside a conductor is zero then why is there an electric current in a resistor when an emf is applied across it for a long time?
0
votes
3
answers
64
views
What is the minimum safe distance a human finger can be placed away from a live contact of 16A, 250V? [closed]
what is the minimum safe distance a human finger can be placed away from a live contact of 16A, 250V and not get shock. Would this distance change if the air was humid?
Would this distance change if ...
0
votes
1
answer
663
views
Current and Ohm's Law in Motional EMF examples
Question:
What causes the current to flow through the whole circuit in the given example? I understand that on the disk there is an emf (integral of force per unit charge) from the centre of the ...
2
votes
2
answers
2k
views
Is it possible to express Fleming's Left Hand Rule and Right Hand Rule in terms of vectors?
I recently studied Fleming's Left Hand Rule and Fleming's Right Hand Rule for electromagnetism (For locating direction of Force, Magnetic Field and Current). Using my hands to find the direction is ...
0
votes
0
answers
246
views
Force Exerting on a magnetic train
A question is already asked ( How does this “simple” electric train work? ). But I've got a question about it.
In order to calculate the force which is being exerted on the system including magnets ...
0
votes
1
answer
211
views
Electric field along a wire and load
I have referred to many books and all of them apply loss in potential across a resistor only in case of circuits. However, the electric field is present in the whole conductor. Hence the electrons ...
0
votes
1
answer
2k
views
What is wavelength of electric field generated in a wire? [closed]
I read link given below:
http://en.wikipedia.org/wiki/Speed_of_electricity
Above link says
_The speed at which energy or signals travel down a cable is actually the speed of the electromagnetic ...
1
vote
0
answers
256
views
How does non-constant conductivity change surface charge on a wire?
Current density is equal to conductivity times electric field. Therefore flux through a cross section of a wire is equal to current over conductivity. Current has to be constant along a wire. This ...