Question

A Rowland ring of mean radius 15 cm has 3500 turns of wire woundon a ferromagnetic core of relative permeability 800. What is themagnetic field B in the core for a magnetising current of 1.2 A?

Answer 1

Given: The radius of ring is 15 cm, number of turns is 3500, relative permeability of core is 800 and magnetizing current is 1.2 A.

The magnetic field is given as,

B= μ r μ 0 NI 2πr

Where, N is the number of turns, r is the radius of ring and I is the magnetizing current.

By substituting the given values in the above expression, we get

B= 800×4π× 10 −7 ×1.2×3500 2π×0.15 =4.48 T

Thus, the magnetic field in the core is 4.48 T.