Linked Questions

1
vote
4answers
200 views

Resistor and voltage drop [duplicate]

I know that a voltage drop of a resistor is the energy lost from the potential energy of the electrons.well, what i am really confused about is why the potential energy of the electron decreases as it ...
2
votes
1answer
52 views

How does electric field propogate in a wire? [duplicate]

When I say electric field, I'm referring to the electric field that causes the movement of charge in the wire. I have learnt about currents and resistances, but I have never really had an ...
21
votes
6answers
10k views

How do electrons "know" to share their voltage between two resistors?

My physics teacher explained the difference between voltage and current using sandwiches. Each person gets a bag full of sandwiches when they pass through the battery. Current = the number of people ...
12
votes
1answer
5k views

What maintains constant voltage in a battery?

I know there's lots of questions that address similar situations, (Batteries connected in Parallel, Batteries and fields?, Naive Question About Batteries, and the oft-viewed I don't understand ...
5
votes
4answers
6k views

What is the physical meaning of electric potential, potential difference, and voltage?

When resembling the electricity flow through a wire to people walking through a street: electrons are people, current is the number of people, resistance is the barriers on the way. But what is the ...
4
votes
5answers
3k views

Why does 0 resistance mean 0 voltage? [duplicate]

According to Ohm's law,$$ \left[\text{voltage}\right]~=~\left[\text{current}\right] \times \left[\text{resistance}\right] .$$Does that mean if there is no resistance, then there can be no voltage? Why ...
9
votes
1answer
5k views

Why does electrical current start to flow?

What happens microscopically when an electrical current starts to flow? I'd like to understand microscopically what happens in detail when electrons start moving (quasi-classically). Electrons can ...
4
votes
4answers
2k views

Electromagnetic field and voltage drop in a circuit

I have been thinking for a while about what really causes voltage drop and how to explain it in terms of what the electric and magnetic fields do. So I've been reading a lot of posts here and in other ...
5
votes
3answers
984 views

What changes in the electrons before and after a voltage drop?

It is easy to visualize gravitational potential energy as a function of the position of height, and a change in this potential is manifested in a change in height. Further, by the work-energy theorem ...
0
votes
1answer
2k views

Why does the sum of the voltage drops have to equal the voltage of the emf source?

My reasoning: Consider a 12V battery. The "12V" tells us that the potential difference between the positive and negative terminal is 12V after our battery undergoes some chemical process. Let's ...
1
vote
3answers
805 views

What is voltage?

I am a little unclear on what voltage actually is and I am trying to find out what the physical cause for voltage is. Is it the speed of the electrons through the conductor or is it an excess of ...
1
vote
2answers
200 views

Stacking batteries and electron flow

About Fuel Cells and Batteries: I understand the analogue with increased water height as two cells (battery or fuel) are connected in series. However if we for instance have two batteries contected in ...
0
votes
2answers
85 views

If there is full voltage drop across a single resistor then how the current flows further in the circuit?

Consider a simple circuit with a battery of constant potential difference V and a resistor of resistance R. So if we close the circuit then current flows through it and there is a voltage drop across ...
0
votes
1answer
61 views

What's the source of voltage? [duplicate]

I've been told that in a DC circuit with a battery the negative terminal of the battery "pushes" electrons in nearby atom away of it and those by themselves cause electrons in other atoms to move, but ...