Answer:
u = 2.01*10^{-4} Am^2
magnetic field strength = 3.91*10^{-8} m
Step-by-step explanation:
a ) magnetic dipole moment i = u / πr^2
where,
i is current in the ring = 100 A
r is radius of ring = 1.60/2 =0.80 mm

u = 2.01*10^{-4} Am^2
b )


magnetic field strength = 3.91*10^{-8} m