Hi there!
We can use the following equation to calculate the magnetic field inside of a solenoid:
[tex]B = \mu_0 ni[/tex]
B = Magnetic Field Strength (T)
n = number of loops PER LENGTH
i = current through solenoid (A)
μ₀ = Permeability of free space (4π × 10⁻⁷ Tm/A)
First, we can solve for 'n' given 'N' (total # of loops) and L (length of solenoid).
[tex]n = \frac{N}{L} = \frac{200}{0.25} = 800[/tex]
Now, we can calculate the magnetic field:
[tex]B = (4\pi \times 10^{-7}) (800)(.29) = \boxed{2.915 \times 10^{-4} T}[/tex]
