Question

A Rowland ring usme ladies 15 CM has 3500 turns of wire round on a ferromagnetic core of relative permeability 800 what is the magnetic field in the core for a magnetization current of 1.2 ampere

• A. 4.48 T
• B. 0.48 T
• C. 0.048 T
• D. 0.448 T

Answer 1

The correct option is A 4.48 T

Given:

Mean radius Of a Rowland ring = 15cm = 0.15 m

Number of turns of a ferromagnetic core =3500

Relative permeability of the core material = 800

Magnetising current = 1.2 A

Solution:

Magnetic field is given by, B =$\frac{U_1\times U_0\times I\times N}{2\times \frac{22}{7}\times r}$

$\Rightarrow B=\frac{800\times 4\times \frac{22}{7}\times {10}^{-7}\times 1.2\times 3500}{2\times \frac{22}{7}\times 0.15}$

$\Rightarrow B=4.48T$

Hence , the correct option is A.