A Flat Circular Coil Having 57 Turns of Very Thin

Short Answer

A flat circular coil having 57 turns of very thin wire has a diameter of 9.5 cm and carries 7.2 A of current. (μ₀ = 4π × 10^-7 T ∙ m/A)
(a) What is the strength of the magnetic field at the center of the coil?
(b) If the same length of wire were used to make a coil with twice the original diameter, how large would the magnetic field at the center be when it carried the same current as before?