- 27th September 2006, 14:21 #1

- Join Date
- Sep 2006
- Posts
- 23
- Helped
- 0 / 0
- Points
- 1,197
- Level
- 7

## The physical significance of curl of a vector

Hi,

Does anybody knows the physical significance of curl of a vector?

- 27th September 2006, 14:21

- 27th September 2006, 23:25 #2

- Join Date
- Sep 2005
- Posts
- 17
- Helped
- 1 / 1
- Points
- 1,409
- Level
- 8

## Re: Electromagnetics

whenever at any point in the space you have changing magnetic field you have curl of the electric field; you get generally non conservative electric potentials; so going a loop in space makes a net change in energy;

- 28th September 2006, 01:56 #3
## Re: Electromagnetics

The physical significance of the curl of a vector field is the amount of "rotation" or angular momentum of the contents of given region of space.

h**p://mathworld.wolfram.com/Curl.html

Mr.Cool

- 12th November 2006, 16:12 #4

- Join Date
- Oct 2006
- Posts
- 17
- Helped
- 1 / 1
- Points
- 1,172
- Level
- 7

## Electromagnetics

curl is a wonderful concept.its what accounts for em wave propagation.imagine a waterpipe closed at one end.now when the liquid flowing in the wire encounters this closed end,it circulates in the pipe this is curl effect.for further details u can always look into feynman's physics book(vol.2 on electromagnetics)

- 12th November 2006, 16:12

- 13th December 2006, 09:05 #5

- Join Date
- Oct 2006
- Posts
- 17
- Helped
- 1 / 1
- Points
- 1,172
- Level
- 7

## Re: Electromagnetics

just like if the end of a pipe is closed at one end,the water circulates in the pipe this is known as curl

- 6th April 2007, 19:49 #6
## Electromagnetics

nijirazdan i like your analogy.

here is the kicker.. your analogy makes it very clear that the energy associated with the curl vector (its moving, so must have energy) is entirely contained WITHIN the pipe.. the water can't leak out of the metal pipe after all..

mathematically speaking, this would be like integrating about the closed path.. where one looks at what is within the border of the integral.

here is the assumption with this analogy and math:

that there is NO energy outside the pipe wall, or if you give the benefit of the doubt, there is no "practically usable" energy outside the wall of the pipe.

what then is the significance of the Heaviside Component?

food for thought...

- 19th April 2007, 12:00 #7

- Join Date
- Oct 2004
- Posts
- 169
- Helped
- 27 / 27
- Points
- 2,614
- Level
- 11

## Re: Electromagnetics

The significance of curl is "rotation".if curl is zero then field is conservative.

- 25th April 2007, 19:35 #8

- Join Date
- Apr 2007
- Posts
- 5
- Helped
- 3 / 3
- Points
- 1,053
- Level
- 7

## Re: Electromagnetics

Originally Posted by**suvendu**

For example, if your x-component of the vector varies as you move along the y or z direction, it will induce a curl. For the nice water pipe analogy mentioned about, the curl is induced at the boundary of the water flow (the transition from a point with flowing water just inside the pipe to just outside the pipe where there is no flowing water).

- 27th April 2007, 21:00 #9

- Join Date
- Aug 2006
- Location
- ankara turkey
- Posts
- 60
- Helped
- 2 / 2
- Points
- 1,607
- Level
- 9

## Re: Electromagnetics

it is the maximun net cirulation as the area about the point goes to zero.

- 29th April 2007, 18:32 #10
## Electromagnetics

curl of a vector gives us the value of twice the angular velocity.