Question

Derive the quantity for Bohr magneton and also state its value.Rowland ring of mean radius 15cm has 3500 turns of wire woundon a Ferromagnetic core of relative permeability 800. What is themagnetic field B in the core for a magnetizing current of 1.2 A?Why do molecules of a liquid in the surface film possess extra​

Answer 1

Answer:

Given data,

Rowland ring is toroid with a core of magnetic material,

Radius of the ring r=15cm

Number of turns of the wire N=3500

Relative permeability of the core,μ

r

=800

Magnetising current, I=1.2A

Magnetic field, B=?

Using the formula for the magnetic field of a torroid,

B=μ

0

nI

Number of turns per unit length, n=

2πr

N

=

2π×15×15

−2

3500

Therefore,

B=μ

0

μ

r

nI

The magnetic field is given by the relation,

B=

2πr

μ

r

μ

0

IN

=

2π×0.15

800×4π×10

−7

×1.2×3500

=4.48T