A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2 A?
Mean radius of a Rowland ring, r= 15 cm = 0.15 m
Number of turns on a ferromagnetic core, N= 3500
Relative permeability of the core material, μr=800
Magnetising current, I= 1.2 A
The magnetic field is given by the relation:
B
Where,
Ã�¼0= Permeability of free space = 4π× 10 - 7Tm A - 1
Therefore, the magnetic field in the core is 4.48 T.
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