A Wire of Radius R = 1

question 17

Multiple Choice

A wire of radius R = 1.5 mm and carries a current.The current density is given by the function J = J₀ (1 - r/R) where r is measured from the center of the wire and J₀ = 1.06 * 10⁵ A/m².Use Ampère's law to find the magnetic field at the surface of the wire.What is the magnitude of B if I = 1A,R = 1.5 mm.

• A)148 µT
• B)12 µT
• C)100 µT
• D)33 µT
• E)37 µT