electrical engineering

<div dir="ltr" style="text-align: left;" trbidi="on"><div style="text-align: center;">A magnetic field is a region in which a magnetic material or a current <a href="http://www.hayatei.blogspot.com/">carrying </a>wire experiences a force. </div><div style="text-align: center;">2.  
A magnetic field is produced by a current carrying wire or a permanent magnet.  
 
</div><div class="O" style="text-align: center;"><div style="color: blue;"> <a href="http://www.hayatei.blogspot.com/">Magnetic Fields of a Bar Magnet </a> 
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<div class="O">1 The direction of the magnetic field at a point indicates the direction of the magnetic force on an isolated north pole placed at that point.  
</div></div><div style="text-align: center;">2 The strength of the magnetic field at a point in space is represented by the concentration (i.e. the spacing) of the field lines.  
</div><div class="O" style="text-align: center;"><div style="color: blue;">Why Are Some Materials Magnetic?  
</div><a href="http://www8.0zz0.com/2010/12/02/13/986591801.jpg" target="_blank"><img border="0" src="http://www8.0zz0.com/2010/12/02/13/986591801.jpg" /></a> 
  
<div class="O">FIn ferromagnetic materials the domains can line up (under the action of an external magnetic field), resulting in the material becoming magnetized. 
FIf the material remains magnetized when the external field is removed (the domains remain aligned), the material is known as a hard magnetic material. 
FIf the material becomes demagnetized when the magnetic field is removed (i.e. the orientation of the domains becomes random again), the material is known as a soft magnetic material. </div></div></div>

What is a magnetic field

A magnetic field is a region in which a magnetic material or a current carrying wire experiences a force. 2. A magnetic field is produced by a current carrying wire or a permanent magnet. Magnetic …

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<div dir="ltr" style="text-align: left;" trbidi="on"><div style="color: red;"> 
</div><div class="O" style="color: red;"><div style="text-align: justify;">FAn electromagnet is a solenoid with a "soft" iron core. </div><div style="text-align: justify;">FIt is a magnet that can be turned on and off by turning a current on or off</div><div style="text-align: justify;">  
<div class="O"><div style="text-align: center;">Electromagnetic Induction </div><div style="text-align: center;"> 
<div class="O"><div style="text-align: justify;">i.Moving a conductor (or a coil) in a magnetic field induces a current / voltage. </div><div style="text-align: justify;">ii.For a current to be induced we must have a closed circuit for the current to flow. Otherwise a voltage is induced. </div><div style="text-align: justify;">iii.The direction of the induced current / voltage can be predicted using Fleming’s Right Hand Rule. </div><div style="text-align: justify;"><div class="O"><div style="text-align: center;">Where Does the Magnetic Energy Come From? </div></div>  
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<div class="O"><div style="text-align: justify;">FA straight wire of length l is moved at right angles (with a velocity v) across a magnetic field of strength B. The wire will have an induced current I flowing through it and will thus experience a motor force on it given by     F = B × I × L </div><div style="text-align: justify;">FLenz’ Law states that the motor force will oppose the movement of the wire (i.e. the force will be in the opposite direction to the wire’s movement). </div><div style="text-align: justify;">FThe rate at which mechanical work is being done (i.e. power) against the motor force is given by    P = F × v = B × I × L × v </div><div style="text-align: justify;">FWe have previously derived an expression for the e.m.f. induced across such a straight wire:   F = B × L × v </div><div style="text-align: justify;">FThe electrical power generated in the wire is then the product of the e.m.f. and the induced current : P =  B × I × L × v = E × I </div></div></div></div></div></div></div>

Electromagnets

FAn electromagnet is a solenoid with a "soft" iron core. FIt is a magnet that can be turned on and off by turning a current on or off Electromagnetic Induction i.Moving a conductor (or a coil)…

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