# Vector potential

1. Jan 29, 2005

### Reshma

The vector potential (A) in a certain region is given by A = xj-yi where i and j are unit vectors.

How will the lines of force look like?

What is the direction of magnetic induction B in the given region of space?

2. Jan 29, 2005

### dextercioby

How about computing the curl and setting it equal to B?

Daniel.

3. Jan 29, 2005

### Reshma

Can please you explain me how you do that? Can you point out to me a chapter in Griffith's book which might help?

4. Jan 29, 2005

### dextercioby

Yes,it surely is the one in which this pops up

$$\vec{B}=\nabla\times \vec{A}$$

Daniel.

5. Jan 29, 2005

### Reshma

Yes, but how does it explain the lines of force?

6. Jan 29, 2005

### dextercioby

Find the vector fields,its components and then u know that this vector field is always tangent to its lines of force...

Daniel.

7. Jan 29, 2005

### Reshma

OK, thanks for the help :-)