Understanding EMF When Area Vector is at 90° with B

  • Thread starter Thread starter admajoremdeigloriam
  • Start date Start date
  • Tags Tags
    Area Emf Vector
Click For Summary
The discussion clarifies that the maximum electromotive force (EMF) occurs when the area vector is at a 90-degree angle to the magnetic field because this orientation allows for the greatest change in magnetic flux per unit time. While the change in flux may remain constant with a fixed angular velocity, the EMF varies due to the continuous change in the area vector's orientation relative to the magnetic field. This dynamic leads to oscillating EMF values, particularly in alternating current (AC) circuits. Understanding this relationship is crucial for grasping how EMF is induced in various contexts. The conversation emphasizes the importance of asking questions to deepen comprehension of complex concepts.
admajoremdeigloriam
Messages
23
Reaction score
0
I don't see the point why EMF is maximum when the Area vector is at a 90 degree angle with the magnetic field (B)

I know that when you consider the equation EMF = NBAw sin(wt) it will show an oscillation with the max when sin(wt) = + or - 1

but when I think about it...
according to Farraday, EMF = -N delta Phi/ delta t
with constant angular velocity, the "change" in flux per unit time is going to be the same no matter what
i do understand that the flux value would be different, but the change would be constant
if this is the case, then EMF should always be constant then
so, how does this apply to ac?

where am I wrong on this? I'm already soooo confused?
maybe i should stick with Organic Chemistry :confused:
 
Physics news on Phys.org
i got it, i forgot that farraday's equation is the average EMF over a time interval
 


It is understandable to be confused about the concept of EMF (electromotive force) and its relationship with the area vector and magnetic field. Let's break it down to better understand why EMF is maximum when the area vector is at a 90 degree angle with the magnetic field.

First, it is important to understand that EMF is the force that drives electrical current in a circuit. It is caused by a change in magnetic flux, which is the amount of magnetic field passing through a given area. This change in flux can be achieved by moving a conductor through a magnetic field, changing the strength of the magnetic field, or changing the orientation of the conductor with respect to the magnetic field.

In the case of the area vector being at a 90 degree angle with the magnetic field, the conductor will be moving parallel to the magnetic field lines. This results in the maximum change in flux per unit time, as the conductor is cutting through the maximum number of magnetic field lines. This leads to a higher induced EMF, as seen in the equation EMF = -N delta Phi/ delta t.

Now, you are correct in saying that the change in flux per unit time would be constant if the angular velocity is constant. However, this does not mean that the EMF will also be constant. As the conductor continues to move in a circular motion, the orientation of the area vector with respect to the magnetic field will constantly change. This results in a constantly changing EMF, which is what we observe in AC circuits.

In summary, the maximum EMF occurs when the area vector is at a 90 degree angle with the magnetic field because it results in the maximum change in flux per unit time. This is important in understanding the behavior of AC circuits and how EMF is induced. I hope this helps clarify your confusion. Remember, it's always okay to seek clarification and ask questions, even if it means stepping out of your comfort zone in organic chemistry. Keep learning and keep asking questions!
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
Replies
6
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
2
Views
1K
  • · Replies 18 ·
Replies
18
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K