Question

A hollow cylinder with an inner radius of 4.0 mm and an outer radius of 30 mm conducts a 3.0-Acurrent flowing parallel to the axis of the cylinder. If the current density is uniform throughout the wire,what is the magnitude of the magnetic field at a point 12 mm from its center

Answer 1

Answer:

the magnitude of the magnetic field is 0.45 mT

Explanation:

Knowing the formula

B = $\frac{m0* (i - i')}{2* Pi* r}$

i = 3A    i' = 0A

B = $\frac{4*3.1416e^{-7} * (3-0) }{2*3.1416*0.012}$

B = 0.45 mT