question about reactance

[m4fiaafg]

can please, someone explain what reactance is, cuz i can understand what it is and what the power triangle has to do with this

 

[Des 56]

In a standard Dc basic circuit using a battery to power a lamp via a switch

The current flow is resisted by the load or lamp and the resistance of the cable
Each cable has different resistances to the flow of current depending on the material of the conductor
So Dc circuits have only resistance

In Ac the resistances are the same,howeve,r because in AC the flow of current is reversed 50 times a second (the frequency)then as the current flows a magnetic field is built up,it then collapses.this happens 50 times a second
A coolapsing magnetic field will induce current flow

This magnetic field as it collapses,it induces an emf(electro motive force)into the current carrying conductor
This force is in opposition to the supply force and therefore is a reactance against the flow of that current

So in AC the oppostion to the flow of current is the sum of the resistance(as in DC)and the back EMF,which is called reactance The total of these are the impedance

Resistance and inductive reactance is impedence in an AC circuit

 

[Wotsit]

Try thinking of it like this

Xl = 2pifL

where Xl is inductive reactance
f is the frequency
L is inductance

Xc =1/(2pifC)

where Xc is inductive capactiance
C is capactance

so considering a series rlc circuit where a voltage source of 100V 100Hz a resistor of 100ohms a inductor of 600mH and a capacitor of 1uf are connected in series we can calculate the resistance of the inductor and capacitor

Zr=100+J0

Zc=0+-J1.59k

Zl=0+j376

we know that for a series circuit that the total impedance is the sum of the individual parts so

Ztotal- Zr+Zc+Zl

so
(250+jo)+(0+-j1.59k)+(0+j357)

=250+J1.233k Ohms

So now you can calculate a circuit impedance


Have a read about complex numbers j notation, thevenin's and nortons equlivent circuit theroum, allaboutcircuits is a good starting place as is advances electrical theory by stroud