3. A coil has N=25 turns. The toroid on which the coil is wound has ID=5 cm and OD=5.5 cm. For a current 1 = 3

Amperes:

a. Calculate the field strength (also called intensity) H along the mean-path length within the toroid.

b. Calculate the field intensity H within the core:

i. Very close to the outside diameter,

ii. Very close to the inside diameter,

iii. Compare the results with field density along the mean path (as in part a.) Show %

differences

c. Calculate the Reluctance in the path of flux lines if u is 2000.

d.

The coil must have an inductance of L = 25 MicroHenries. The maximum current is 3A and the

maximum Flux Density B is not to exceed 1.3 T. Calculate the number of turns N and the relative

permeability of the core material μ...

Hint for part d: L = N² / Reluctance

H in a Toroid

1(ID+OD

Mean radius, 1

1-2m

Ampere's Law H.-

Ni Ni

2