Hi there, im doing an doing a question from a tutorial sheet in power engineering, here is the question: (im not looking the answer to the question)
A ferromagnetic core has mean path length
l1 of 50 cm. There is a small gap of 0.1cm in the structure
of the otherwise whole core. The cross-sectional area of the core is 15 cm
2, the relative permeability of
the core is 4000 and the coil of wire on the core has 500 turns. Find:
(1) the total reluctance of the flux path (iron plus air gap), and
(2) the current required to produce a flux density of 0.6 T in the air gap.
What I am unsure about is the when i look at the solution to the question I understand the formula but not why the cross sectional area of the core is written to be 0.0015m^2 or 15 x 10^-4. I say this as would it not be written as 0.15m^2 or 15 x 10^-2, could you explain why?
Aprreciate your help,
Ben
