# Different type of solenoid design help

1. Aug 8, 2012

### JuanMotta

Hi my name is Juan Motta and i´m new in this forum, I`m a total begginer in physics. I´m planning to build a solenoid (air coil or iron coil, i don´t know) with different form, like this:

http://www.divshare.com/img/thumb/19310413-b22.jpg

And i have some cuestions about, because i have some formulas from this forum but they are applicable with a cylinder form, how can i estimate the gauss from this type of solenoid?

Thanks and sorry about my english

Juan Motta

2. Aug 8, 2012

### GarageDweller

What do you mean what "gauss", the magnetic flux density varies from place to place.
If you are referring to the approximately constant field inside the solenoid, there is a well known formula for it.

3. Aug 8, 2012

### JuanMotta

Sorry... and "Yes" is the approximately constant field inside the solenoid, but i don´t know how can i estimate in this type of shape because is not a cylinder....

4. Aug 8, 2012

### Staff: Mentor

As long as the coil length is much larger than the "width", the shape should not be important. Just use the formula for cylindrical coils. If the coil is not long compared to the width, you will need integrations to calculate it (probably numerically).

5. Aug 8, 2012

### JuanMotta

Yes, the coil is not long, is short, so integrations for the for calculate the radius?.... I think I'm very far to get to know that.....

6. Aug 8, 2012

### GarageDweller

Look into amperes law, the field can be quite difficult to find for current densities without good symmetry

7. Aug 9, 2012

### Staff: Mentor

You cannot use Amperes law (no straight wire of infinite length), you need Biot-Savart to calculate the magnetic field.

8. Aug 9, 2012