A solenoid has a core of a material with relative permeability 400. The windings of the solenoid are insulated from the core and carry a current of 2A. If the number of turns is 1000 per metre, calculate (a) H, (b) M, (c) B and (d) the magnetising current Im.
Calculate H.
H = ³ A/m
Calculate M.
M ⁵ A/m
Calculate B.
B = 1.0 T
Calculate the magnetising current Im.
Im = 794 A
Explanation
This numerical problem from Example 5.5 tests understanding of magnetic quantities in a solenoid with a magnetic core. The key concept is that H (magnetic field intensity) depends only on the current and number of turns, not on the core material. The magnetisation M arises due to the magnetic material, and the magnetising current represents the equivalent additional current needed to produce the same B field without the core.