Permanent magnets, Electrical Engineering

Assignment Help:

Materials with 'hard' magnetic B/H characteristics often show a strong residual magnetism. This makes them suitable for making permanent magnets. If the ring material were magnetised, then the magnetised material itself will create a flux in the ring. No current carrying coil will be required.

1915_permanent magnets.png

 

For a permanent magnet, flux is produced by the alignment of magnetised domains within the material itself. (c.f earlier notes relating to residual magnetism in B/H curve).  In this case, the flux exists without the need for a coil, i.e. N.I = 0. Hence applying Ampere's Law results in:

 

1504_permanent magnet.png

Hence eqn 1 and the B/H curve must be simultaneously satisfied and to give the flux density and magnetic field strength in the magnetic material (and hence also the air gap)

 

1077_permanent magnet 1.png

 

 

from equation (1)  Bc/Hc=-Lc/Lgµ0         

 

which is slope of a straight line. The flux density and magnetic field in the magnetic circuit is given by the point at which eqn (1) cuts the B/H curve. Permanent magnets are widely used in transducers:- loud speakers, measuring meters, D.C. motors etc.

 


Related Discussions:- Permanent magnets

Requirement specification for the monitor and alarm system, Prepare a User ...

Prepare a User Requirement Specification for the monitor and alarm system. User Requirements Specification should be written in a clear and unambiguous manner to state: • The

Calculate the impedance, What is the impedance Z between terminals A and B ...

What is the impedance Z between terminals A and B of the networks shown below? Express your answers in polar form. Three voltages represented by v 1 (t)=100cosωt, v 2 (t)=7

Factors involved in the voltage build up of shunt generator, Q.   List and ...

Q.   List and explain the factors involved in the voltage build up of shunt generator. Ans. following factors are involved in voltage build up of shunt generation

Consumer interaction and service standards, Consumer Interaction and Servic...

Consumer Interaction and Service Standards These KPIs deal along with the customer, internal business procedures and change management. These are significant to give the desir

Covert analog signal into digital signal, Covert Analog Signal into Digital...

Covert Analog Signal into Digital Signal A strain gauge is used in Wheatstone Bridge configuration. The output from the Wheatstone Bridge varies from zero to a maximum strain

Different types and uses of delay line in cro, Q.   What are the different ...

Q.   What are the different types and uses of delay line in CRO? OR Why is a delay line used in the vertical section of the oscilloscope? Sol. All electronic circui

Mutual inductance and coefficient of coupling, Mutual inductance and coeffi...

Mutual inductance and coefficient of coupling: The equivalent inductance of two series connected coil (with mutual inductance among them) is 0.8 or 0.2 Henry based on the rela

Introduction to electronics, Explain the difference between a microprocesso...

Explain the difference between a microprocessor and an embedded microcontroller

Explain analog communication system, Q. Explain Analog communication system...

Q. Explain Analog communication system? Analog signals in an analog communication system can be transmitted directly via carrier modulation over the communication channel and d

Explain the suitability of aluminium, Explain the suitability of aluminium ...

Explain the suitability of aluminium  that is used as electrical conducting materials. Aluminium : Conductors are appropriate for ambient and very high temperature. Use of alu

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd