What do you mean by magnetic circuits, Electrical Engineering

Assignment Help:

Q. What do you mean by Magnetic circuits?

A magnetic circuit provides a path for magnetic flux, just as an electric circuit provides a path for electric current.Magnetic circuits are integral parts of transformers, electric machines, and many other common devices such as doorbells. Analogous to voltage (electric potential difference) in the electric circuit, in a magnetic circuit we have the magnetomotive force (mmf), or the magnetic potential difference which produces a magnetic field, and which has units of amperes or ampere turns. The two sources of mmf in magnetic circuits are the electric current and the permanent magnet (which stores energy and is capable of maintaining a magnetic field with no expenditure of power). The current source is commonly a coil of N turns, carrying a current I known as the exciting current; the mmf is then said to be NI At.

184_What do you mean by Magnetic circuits.png

Figure (a) shows, schematically, a simple magnetic circuit with an mmf ℑ (= NI) and magnetic flux φ. Note that the right-hand rule gives the direction of flux for the chosen direction of current. The concept of a magnetic circuit is useful in estimating the mmf (excitation ampere-turns) needed for simple electromagnetic structures, or in finding approximate flux and flux densities produced by coils wound on ferromagnetic cores.Magnetic circuit analysis follows the procedures that are used for simple dc electric circuit analysis. Calculations of excitation are usually based on Ampere's law, given by

999_What do you mean by Magnetic circuits1.png

where H(| ¯H|= B/µ) is the magnetic field intensity along the path of the flux. If the magnetic field strength is approximately constant (H = HC) along the closed flux path, and lC is the average (mean) length of the magnetic path in the core, Equation can be simplified as

2324_What do you mean by Magnetic circuits2.png

Analogous to Ohm's law for dc electric circuits, we have this relation for magnetic circuits,

2040_What do you mean by Magnetic circuits3.png

where µ is the permeability, A is the cross-sectional area perpendicular to the direction of l, and l stands for the corresponding portion of the length of the magnetic circuit along the flux path. Based on the analogy betweenmagnetic circuits and dc resistive circuits, Table summarizes the corresponding quantities. Further, the laws of resistances in series and parallel also hold for reluctances.

 


Related Discussions:- What do you mean by magnetic circuits

Show basic construction of mosfet, Q. Show Basic Construction of MOSFET? ...

Q. Show Basic Construction of MOSFET? The basic construction of the n-channel depletion-type MOSFET is provided in Figure. A slab of p-type material is formed from a silicon

Lc circuits, L=0.0053nH, C=15µF find the operating frequency of series LC c...

L=0.0053nH, C=15µF find the operating frequency of series LC circuit. What factors decides capacitance ..

What are the constructional features of dc machines, Q. What are the Constr...

Q. What are the Constructional Features of DC Machines? Adc generator ormotormay have asmany as four fieldwindings, depending on the type and size of the machine and the kind o

Control system, .I need some help for doing my assignment

.I need some help for doing my assignment

Electricity hazards in the laboratory, ELECTRICITY HAZARDS IN THE LABOR...

ELECTRICITY HAZARDS IN THE LABORATORY : You've probably read about, or heard of, people falling onto high voltage rails or cables and surviving thousands of volts. As a contra

Electrical machine, Design a suitable double –layer lap winding for a 6-pol...

Design a suitable double –layer lap winding for a 6-pole dc armature with 18 slots and two coil sides per slot. Give values of front-pitch, brack–pitch and commutator pitch. Draw t

Evaluate reference voltage, Q. Consider the 4-bit R-2R ladder D/A converter...

Q. Consider the 4-bit R-2R ladder D/A converter with V ref =-10 V. Determine the analog output voltage when the binary input code is 1100. Also, find what reference voltage is to

Dsp., fir and iir filter design

fir and iir filter design

What is the purpose of segment registers in 8086, What is the purpose of se...

What is the purpose of segment registers in 8086? There are 4 segment registers present in 8086. They are 1. Code Segment (CS ) register 2. Data Segment (DS ) register

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