Exercise 01

Determine the reluctance of the air gap of a machine whose apparent surface area is S_a=4,6 .10^-2 m² and the length is l_a=5,6 mm.

Exercise 02

The magnetic circuit in the figure below is made of cast iron. It has a mean length l_i=0,44 m and a square cross section of 0,02 m on each side. The length of the air gap is l_a=2 mm and the coil has N=400 turns.

1. Find the current I necessary to establish a flux of 0.141 mWb in the air gap.

Exercise 03

We consider a coil of 5000 turns whose resistance is 200 Ω.