Anna University Solved Problems

ANNA UNIVERSITY SOLVED PROBLEMS

1. A magnetic field strength of 2 × 105 amperes / metre is applied to a paramagnetic material with a relative permeability of 1.01. Calculate the values of B and M 

Given data

Magnetic field strength H = 2 × 105 A/m

Relative permeability μr = 1.01

Solution

We know that M / H = μr -1

M = H (μr - 1)

Substituting the given values, we have

= 2 × 105 (1.01 – 1)

M = 2 × 103

B = μo (M + H)

= 4π × 10-7 (2 × 103 + 2 × 105)

= 4π × 10-7 (0.02 × 105 + 2 × 105)

= 4 π × 10-7 (2.02 × 105)

B = 0.2537 Wbm2

2. Magnetic field intensity of a paramagnetic material is 104 ampere/metre. At room temperature its susceptibility is 3.7 × 10-3. Calculate the magnetization of the material.

Given data

Magnetic field intensity H = 104 ampere / metre

Susceptibility χ = 3.7 × 10-3

Magnetization of the material = ?

Solution

We know that Magnetization = χ H

Substituting the given values, we have

= 3.7 × 10-3 × 104

M = 37 ampere / metre