# Homework Help: Calculating the Number of loops in the solenoid

1. May 16, 2012

### spideykid7

1. The problem statement, all variables and given/known data

The mathematical formula that connects the magnetic field in a solenoid with the current is given by B=((μ0 x n)/(2πr)) i

where μ0 = 4∏ x 10^-7 NA^-2 is the 'magnetic constant', n is the number of turns or loops of wire (unknown), r is the radius of the solenoid (0.023m), and i is the solenoid current.

Use the slop of your line to approximate the number of turns or loops in the solenoid.

the equation of the line is: y=0.0054x + 0.0004

Solenoid Current Values:
1. 3.0A
2. 2.5A
3. 2.0A
4. 1.5A
5. 1.0A
6. 0.8A

B Values (numbers match up with Solenoid Current)
1. 1.60 x 10^-2
2. 1.40 x 10^-2
3. 1.20 x 10^-2
4. 0.85 x 10^-2
5. 0.58 x 10^-2
6. 0.43 x 10^-2

URGENTLY NEED HELP!!! PLEEEAASSEE!!

2. May 16, 2012

### cragar

You equation for your B field inside your solenoid does not seem correct.
The field inside a solenoid is constant and does not depend on the radius.
$B= \mu_0 n I$ where n is turns per length. unless you are talking about a toroid.
And also how would you figure out the slope of the line.

Last edited: May 16, 2012