Basic electromagnetic principles, Electrical Engineering

Assignment Help:


It has been known for a thousand years or more (originating in China) that certain (magnetic) materials would always orientate    themselves in a  particular direction if suspended to rotate freely. The very earliest experiments in magnetism were done with these materials (permanent magnets)  and  these  clearly  showed  that two pieces of these materials were able to exert some force at a distance. This force is analogous to gravitational force. We know from our own experience that it exists. Physicists theorise on the causes whilst engineers are more concerned with being able to measure the practical effect and put it to use by devising a suitable method of analysis.

Very early experiments by Oersted and Ampere showed that a current carrying conductor also had an effect on magnetic material    in    its  vicinity.   Magnetic compasses   placed    near    to    a    current carrying conductor were deflected. He also found that the direction of deflection depended on the position relative to the wire. Those above the wire were deflected in the opposite direction to  those placed below. Ampere quantified the strength of this force in terms of the current and the distance involved.
 

In    order  to  be    able   to  relate   these observations to analysis, the concept of a magnetic field was introduced.The presence of a magnetic field may be visualised  by  drawing   imaginary continuous  lines  of    'magnetic  flux',  the density of which is a measure of the strength of the field  in a given material. Arrows are added to the flux lines to indicate the direction of the magnetic field, from which the  direction  of the  force  it produces on, for example, compass needles and current carrying conductors can be deduced. Convention has it that the magnetic field strength is denoted by the symbol H  (ampere.turns),  whilst magnetic  flux density  is  given  the symbol B (Webers/m2).


Related Discussions:- Basic electromagnetic principles

FET operation, ON output plot of a JFET n-channel transistor if ID is close...

ON output plot of a JFET n-channel transistor if ID is close to IDSS does the value of VGS close to VP?

Ac, power factor improvement

power factor improvement

Define shunt var compensation, Define Shunt VAr Compensation? Shunt cap...

Define Shunt VAr Compensation? Shunt capacitors absorb leading VArs (i.e. they are used to supply lagging VArs) whereas reactors are used to absorbs lagging VArs. Capacitors an

Voltage, the relation between power

the relation between power

Determine the resultant line current and power factor, Q. A three-phase loa...

Q. A three-phase load, connected to a 440-V bus, draws 120 kWat a power factor of 0.85 lagging. In parallel with this load is a three-phase capacitor bank that is rated 50 kVAR . D

Electronics, determine mimimum SOP for the following swiching funcion using...

determine mimimum SOP for the following swiching funcion using K-map: F(x1,x2,x3,x4)=Summationof m(4,6,8,10,11,12,15)+DC(3,5,7,9)

Help assignments, A three-phase transposed line is composed of one conducto...

A three-phase transposed line is composed of one conductor per phase with flat horizontal spacing of 11 m as shown in Figure 1(a). The conductors have a diameter of 3.625 cm and a

8 bit data to register - move immediate instruction , 8 bit  data to Regi...

8 bit  data to Register   This form  of the  instruction is used to copy 8 bit  data directly  to the register  location specified in  the instruction. The  instruction format i

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