How can a magnetic field generate a Potential Difference?

[Muhammad Usman]

Problem Statement: Potential difference is the difference in the quantity of charge in both potentials. How does the magnetic field creates this difference of charges ?
Relevant Equations: None

Hi,

I was reading electricity and found that the difference in potential of both end is the difference in the quantity of the charges on the both ends (More positive charge and less positive charge or vice versa). In the mechanism of generation of electricity a metal coil is rotated in magnetic field and current is generated due to variation in the magnetic field. What I don't understand that how does the difference in potential will create this difference in charges ?

 

[anorlunda]

Charge unbalance is one way to create a voltage difference. Current flowing through a resistor is another way to create a voltage difference.

Magnetic fields and motion are one way (not the only way) to produce current.

 

[Muhammad Usman]

I don't understand current flowing through a resistor

 

[anorlunda]

I don't understand current flowing through a resistor

How much backgound do you have with study of basic electricity and circuits?

 

[Muhammad Usman]

Oh ... I thought you mean something else. I understand with resistor there is voltage drop and you have different potential difference at both terminals.

 

[Muhammad Usman]

But that potential difference is supplied by the battery.

 

[berkeman]

If you connect a loop of wire to a resistor, and wave a magnet in front of that loop of wire, you can measure a voltage being developed across that resistor. This is how electric generators and electric motors work.

As @anorlunda asked, what is your background in learning about electricity and circuits? These concepts can be explained using calculus and Maxwell's equations, but if your background is more basic so far, we can do our best to explain what is going on in more basic terms. We are happy to help you learn about this.

 

[ZapperZ]

Problem Statement: Potential difference is the difference in the quantity of charge in both potentials. How does the magnetic field creates this difference of charges ?
Relevant Equations: None

Hi,

I was reading electricity and found that the difference in potential of both end is the difference in the quantity of the charges on the both ends (More positive charge and less positive charge or vice versa). In the mechanism of generation of electricity a metal coil is rotated in magnetic field and current is generated due to variation in the magnetic field. What I don't understand that how does the difference in potential will create this difference in charges ?

Based on this and the title of your thread, I think there is a more fundamental issue with your understanding of magnetic induction. So let's start with a simpler case.

Can you understand how there can be an induced potential difference (emf) between the two ends of the conducting bar that is moving in the uniform magnetic field, as shown in the figure below? This is a direct application of the Lorentz force law, and also Faraday's law.

Zz.

 

[vanhees71]

It is utmost important to understand that at presence of a time-varying magnetic field there is no potential for the electric field. According to Faraday's Law of induction, which is one of the Maxwell equations, a time varying magnetic field implies an "electric vortex" (in SI units):
$$\vec{\nabla} \times \vec{E}=-\partial_t \vec{B}.$$
The EMF is NOT a voltage, i.e., no potential difference!

It's a very good idea to think about the problem posed in #8. You can solve it in several ways. To use the Lorentz force law is the most physical and simple one in this case. The use of Faraday's law in integral form is a bit subtle, because you need consider the integration over a time-changing surface and its boundary. See the following very nice derivation in Wikipedia:

https://en.wikipedia.org/wiki/Faraday_paradox#Faraday's_law_compared_to_the_Maxwell–Faraday_equation
You'll see that both ways lead to the same result.

 

[Muhammad Usman]

If you connect a loop of wire to a resistor, and wave a magnet in front of that loop of wire, you can measure a voltage being developed across that resistor. This is how electric generators and electric motors work.

As @anorlunda asked, what is your background in learning about electricity and circuits? These concepts can be explained using calculus and Maxwell's equations, but if your background is more basic so far, we can do our best to explain what is going on in more basic terms. We are happy to help you learn about this.

Hi Thanks for the response. There is one more question that comes in my mind. Can you please help in this regard ?

In the below figure they mentioned there are two ways the force exerted, one is from north and and one from south pole. Does electron experience a push or pull from the magnetic field as the pink and blue arrow represents and if yes they are in the same direction (As per flow of electrons) so what is the potential on the end at the north pole of the magnet. Is it the same as the one on the south side but in opposite direction. Let's suppose at point B it is 10V. What is the potnetial at point A, is it -10 V or 0).