Linked Questions

20
votes
6answers
9k 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 ...
10
votes
6answers
4k views

Explaining Walter Lewin's “Complete Breakdown of Intuition”

This Walter Lewin lecture hinges on the solenoid producing a non-conservative field. I read in the Feynman Lectures that "all the fundamental forces in nature appear to be conservative" (Vol 1, 14.5) ...
5
votes
3answers
14k views

Non-conservative electric fields due to changing magnetic flux?

What I read in several places, tells me that, the fact Coulomb's Law follows inverse-square law and gives a force which is radial, implies that a static electric field must be conservative.(In short, ...
1
vote
6answers
1k views

Potential difference between 2 points in a loop containing changing magnetic field = 0?

I came across this question in an exam. The answer to this was given as YES. But I think otherwise. They say between A and B, there is zero potential difference. But if i simply alter the diagram a ...
5
votes
1answer
713 views

Calculate the charge distribution given the potential $\Phi(x,y) = 2(\tan^{-1}(\frac{1+x}{y}) + \tan^{-1}(\frac{1-x}{y}))$ [closed]

So this problem actually comes from The Classical Electromagnetic Field by Leonard Eyges and says: Find the distribution of charge giving rise to an electric field whose potential is $\Phi(x,y) = 2(...
0
votes
1answer
597 views

Very short ($\ell \ll \lambda$) dipole as a receiving antenna

I'm trying to understand how a very short dipole of length $\ell \ll \lambda$ works for receiving radiation. (It is center-fed, and has two thin perfectly conducting arms each of length $\ell/2$ ...
2
votes
1answer
656 views

Confusion about induced emf vs motional emf

Faraday's law says that the change in magnetic flux through the area enclosed by a wire loop induced an emf in the circuit. What exactly is this induced emf? If I understand correctly, it is the ...
1
vote
1answer
287 views

Electric field lines forming closed loops

I have been reading about the electric field induced on a metal ring due to an increasing magnetic field directed along the axis of the ring and the electric field lines are found to form concentric ...
1
vote
2answers
198 views

How is voltage proportional to current?

The question came up in another forum - "What causes current to flow". Many knowledgeable people explained that what causes the flow of charge are electric field forces or Coulomb forces. If there is ...
0
votes
0answers
129 views

Potential difference and voltage

Is potential difference between two points the voltage? (or) Is voltage the potential difference between two points? (or) Are they both the same?
1
vote
0answers
128 views

How is mass flow rate an inexact differential?

How is mass flow rate within an annular region of a pipe taken to be an inexact differential? EDIT: I read it in Fluid Mechanics textbook by Yunus A. Cengel and John M. Cimbala. The mass flow rate ...
1
vote
0answers
86 views

Are the electric and magnetic fields conservative vector fields?

I have read that magnetic and electric fields have both a direction and a magnitude but I am somewhat confused as to whether they are conservative , the curl being zero. Electrostatic fields are ...