# Search results

1. ### B Current in a circuit

Just in general when we talk about voltage in ohms law. Can it be between points or between non-points? What is voltage if we’re not referring to single points? I’ve understood voltage to be a difference in electrical potential between two points.
2. ### B Current in a circuit

Is voltage always measured between theoretical points? Also, if the physical dimensions of the wire don’t matter when finding this sort of thing, why are wires treated as infinityley thin in circuit analysis? I would think that there wouldn’t be a size assigned if it was trivial.
3. ### B Current in a circuit

But if the amount of charge flowing through a given point per unit time was .5A, wouldn’t the amount of charge flowing through a cross section be infinite because there are an infinite number of points on the cross section?
4. ### B Current in a circuit

How can it be both? If there was a certain finite amount of charge flowing through the cross section of a wire wouldn’t the amount of charge flowing through a point on that cross section have to be nearly 0? Also sorry for the similar post, I realized that I was still a bit confused on this...
5. ### B Current in a circuit

If we measure the voltage in a simple series circuit to be 5v and the resistance to be 10 ohms. The current given is .5A. Is this the amount of chage traveling from the first point to the second point per unit time, or is it the amount of charge flowing through a cross section of the conductor...
6. ### Coefficient of kinetic friction lab

I believe the a would come from the fact that F = ma. Replace F with M1a on one side and with M2a on the other. I think we can also get rid of T by substitution.
7. ### Coefficient of kinetic friction lab

Homework Statement I need to find the coefficient of kinetic friction from a set a lab data that I found. I had a mass connected to a mass hanger by a pulley, and measured the acceleration of the mass with various amounts of mass on the hanger. In the attached image, the acceleration was...
8. ### B Meaning of Current in Ohm's law

So if R is the resistance between a point at the beginning and at the end, and V is a voltage between a point at the beginning and at the end, V/R would be the current coming from the beginning and entering the end of the circuit? It can’t be the current along the entire path between the two...
9. ### B Meaning of Current in Ohm's law

If we had a parallel circuit with a voltage of V between the beginning and end, and the circuit has a resistance R, then the current given by ohms law is I = V/R. What does this mean? The current is not the same throughout the whole circuit. Where is the current equal to this value?
10. ### I Improper integrals

Wouldn’t that definition of an integral rule out definite integrals as integrals?
11. ### I Improper integrals

I understand what improper integrals are, but are they really integrals? The semantics are just a bit confusing.
12. ### B Ohmic and non-Ohmic conductors

But aren’t there ways to find resistance without measuring it? So at any instant, the value of R would have to be a single value based on resistivity, length and area? The statement seems stronger than just saying that there exists some current and some voltage.
13. ### B Ohmic and non-Ohmic conductors

Do ohmic conductors obey ohms law at high voltages? Also, I’ve seen it explained that some conductors are non-ohmic because the temperature caused by the current changes the resistance in the circuit. If that’s the case, isn’t ohms law still being obeyed, just with a varying resistance.
14. ### B Voltage drop over a resistor

So is there no force on the charge carriers while going through a wire, but some force on charge carriers going through a resistor. And if so what is the cause of that force.
15. ### B Voltage drop over a resistor

why does it have to do either? If you push a block with a constant velocity along a frictional surface, energy is being lost similarly to in the resistor. But the block doesn’t gain or lose any kinetic or potential energy as it’s pushed. Is this situation not analogous to current through a...
16. ### B Voltage drop over a resistor

My bad, that was worded poorly. I meant to ask why the electrical potential is greater at a point before the resistor than a point after the resistor.
17. ### I Improper integrals

if I wanted to take the definite integral of 1/x with respect to x, with the bounds -1 and 1, the integral would be improper. What about the indefinite integral? We can find the indefinite integral of 1/x to be ln|x|. Can we find the indefinite integral of discontinuous functions?
18. ### B Voltage drop over a resistor

Why is the electrical potential greater before it passes through a resistor than after?
19. ### B Current without voltage

in a circuit like the one in the attached picture, the voltage between two points in between two resistors should be 0. But there is current flowing through the circuit. So what’s going on here? Does ohms law not apply in this situation for some reason?
20. ### B Voltage in a series circuit

I believe 0 for question 3 and 9v for question 4.
21. ### B Voltage in a series circuit

I want to say that it will measure 9v for question 2. My intuition along with the responses make me think that voltage is only found between resistive parts of a circuit.
22. ### B Voltage in a series circuit

Yes there’s a power supply. Here’s a picture of something like what I’m thinking of. My intuition from having used a voltmeter before is that it would be the same everywhere. Although of my intuition is correct, I’m left a bit confused. A flowing body of water on an incline is often used to...
23. ### B Voltage in a series circuit

If I had a simple series circuit with only a single resistor, and I used a voltmeter to find the voltage between a point at the end of the circuit and another point, which was moved from the beginning to the end of the circuit, what would I find at these various point? Would the voltage remain...
24. ### I What Must Conductors be Made of

I don’t think I’m looking for a conductor that isn’t a conductor. I’m just curious about how conductors we’re understood before we knew about the electron. Maybe I’m wrong but I believe the idea of conductors did come first. I understand that a metal is made of protons, neutrons, and electrons...
25. ### I What Must Conductors be Made of

What would be a simple definition of a conductor? When I look it up I find things like, a material that conducts electricity, or an object that allows the flow of current, but these definitions seem like they aren’t as useful as they could be. Is there a definition that isn’t circular and...
26. ### I What Must Conductors be Made of

I’m not sure what would keep them together. I’m asking this question to see I there is some way of understanding how conductors work without having to have a strong understanding of how real world particles interact. I was thinking through some non-electromagnetic force like the strong nuclear...
27. ### I What Must Conductors be Made of

Does their need to be both positive and negative charge carriers? Or could you theoretically have a conductor with only one or the other?
28. ### I What Must Conductors be Made of

When we think of conductors in an abstract sense, charges can flow freely through them. What are these abstract conductors made of? I understand that conductors in the real world are made primarily of protons and electrons, But that it doesn’t seem like that is necesarrily the case. If we had...
29. ### B Representing Vectors

I recently had a test question where I had to calculate a force on a charged particles from two other charges particles. The answer ended up having an x and a y component. I realized I wasn’t quite sure how to represent that vector. Should I just have written it as something like 5Nx^ + 6Ny^...
30. ### I Dx as a small change in x

Can you explain what this means in layman’s terms? Also, is this a somewhat controversial question? I’ve had a hard time looking for answers, partially because some of the answers I’m seeing seem contradictory. Some mention infitessimals, others seem dismissive of infitessimals or don’t...