# Homework Help: Magnetic Field Strength (Integral needed)

1. Mar 2, 2010

### smellsey

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

You have 10 m of 0.55 mm diameter copper wire and a battery capable of passing 13 A through the wire. What magnetic field strength could you obtain inside a 2.8 cm diameter solenoid wound with the wire as closely spaced as possible?

2. Relevant equations

Turns of a solenoid = length of wire/ (2$$\pi$$ * radius of solenoid)

B = ( $$\mu$$*turns of a solenoid * Current)/($$\sqrt{}(4(radius of solenoid)^2+(radius of copper wire)^2$$ where $$\mu = 4\pi *10^-7$$

I believe thats right once you do the integration

3. The attempt at a solution

I tried to solve this and I got B = 0.27 T but it isn't right! I've tried over and over again, but I can't see to get the right answer.

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

2. Relevant equations

3. The attempt at a solution

2. Mar 2, 2010

### ideasrule

Why do you need integration? Can't you use the formula for the magnetic field inside a solenoid?

3. Mar 2, 2010

### smellsey

Well...you could be right. How would you do that?