- #1

DivergentSpectrum

- 149

- 15

What is S? I know it has to be an open surface for the flux integral to be non-zero, but over what surface do i do the integral?

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter DivergentSpectrum
- Start date

- #1

DivergentSpectrum

- 149

- 15

What is S? I know it has to be an open surface for the flux integral to be non-zero, but over what surface do i do the integral?

- #2

Doc Al

Mentor

- 45,473

- 1,976

That should be the induced EMF, not current.As i understand, the inducedcurrentin a wire equals -d(∫∫B⋅dS)/dt

Consider the surface bounded by the wire.What is S? I know it has to be an open surface for the flux integral to be non-zero, but over what surface do i do the integral?

- #3

DivergentSpectrum

- 149

- 15

so the loop has to be closed then?

- #4

jtbell

Mentor

- 15,969

- 4,775

- #5

DivergentSpectrum

- 149

- 15

So if the circuit is open there is no voltage generated?

- #6

jtbell

Mentor

- 15,969

- 4,775

- #7

DivergentSpectrum

- 149

- 15

interesting... i wish the book i read had put it that way. i never even knew the curl of the electric field could be non-zero this really gives me a whole new perspective of what's going on here

- #8

jtbell

Mentor

- 15,969

- 4,775

i never even knew the curl of the electric field could be non-zero

You started with electrostatics in which ##\vec E## does not change with time, and magnetostatics in which ##\vec B## does not change with time. In those situations, ##\vec \nabla \times \vec E = 0## so ##\vec E## is a conservative field and you can define the electric potential. Now you're starting on electrodynamics (time-varying ##\vec E## and ##\vec B## fields) in which this is no longer the case.

Pretty soon you'll see Maxwell's Equations all together in their glory.

(This stuff was what made me decide to be a physics major, by the way!)

- #9

DivergentSpectrum

- 149

- 15

lol awesome i know relativity is up next so I am getting pretty excited

Share:

- Last Post

- Replies
- 2

- Views
- 318

- Replies
- 4

- Views
- 745

- Replies
- 78

- Views
- 4K

- Last Post

- Replies
- 5

- Views
- 2K

- Replies
- 4

- Views
- 472

- Last Post

- Replies
- 4

- Views
- 364

- Replies
- 2

- Views
- 394

- Replies
- 11

- Views
- 1K

- Last Post

- Replies
- 2

- Views
- 607

- Last Post

- Replies
- 6

- Views
- 853