Answer / shvetang dave

Real power is active powe whichis used to do work or to
produce energy & it is V*A*Cos phi whreas reactive power is
the power which is used to magnetise the magnetic field in
electrical motors,transformers,electrical ballasts etc..and
it is V*A*sin phi

Answer / aurobindo sahoo

power used in da loads are real and that being wasted culd
be termed as reactive.real is da useful one.

Answer / vasanth kumar s m

Alternating current
In alternating current circuits, energy storage elements
such as inductance and capacitance may result in periodic
reversals of the direction of energy flow. The portion of
power flow that, averaged over a complete cycle of the AC
waveform, results in net transfer of energy in one
direction is known as real power (also referred to as
active power). That portion of power flow due to stored
energy, that returns to the source in each cycle, is known
as reactive power.


Power triangle The components of AC powerThe relationship
between real power, reactive power and apparent power can
be expressed by representing the quantities as vectors.
Real power is represented as a horizontal vector and
reactive power is represented as a vertical vector. The
apparent power vector is the hypotenuse of a right triangle
formed by connecting the real and reactive power vectors.
This representation is often called the power triangle.
Using the Pythagorean Theorem, the relationship among real,
reactive and apparent power is:

(apparent power)2 = (real power)2 + (reactive power)2
Real and reactive powers can also be calculated directly
from the apparent power, when the current and voltage are
both sinusoids with a known phase angle between them:

(real power) = (apparent power) * cos(theta)
(reactive power) = (apparent power) * sin(theta)
The ratio of real power to apparent power is called power
factor and is a number always between 0 and 1.

To know the Power Triangle & the above concept here is the
hyperlink for this sub:
http://en.wikipedia.org/wiki/Power_factor#Importance_of_powe
r_factor_in_distribution_systems

Answer / pkd

real power is that which is really consumed by a load(resistive load) & which can not be reactive again or which can not be transferred to the source by the load.
reactive power is that which is consumed(inductive load)or store (capacitive load)power for a certaim period of time which can be reactive,that is which can be transferred to the source from the reactive load(capacitive/inductive)for another certain period of time.
so real power is caused due to the electric energy which actually/really works to transform into heat or another means of energy in the load(resistor),but reactive power is due to the energy which is not actually lost due to the friction or anything other in the load,rather it can be transferred to the source again.

now it is easy to say what is more important or both are important..

Answer / mahesh ch

both r useful......but reactive power just for production of magnetic field enough.....if it is more means lagging pf...that makes disadvantages.

Answer / kamlesh dewangan

Active & Reactive power can be easily understood by thier
formula:

P=V*I*cos@
but cos@=R/Z
so P=V*I*R/Z
also V/Z=I
so P=I(sqr)R
This is the formula for heat loss in the system. Actully no
any system is loss less. so active power is the power that
is lost in the form of heat in the systeor we can say
Active is the power used in the system to compensate
for loss.

simillarly
Q=V*I*sin@
but sin@=X/Z
so Q=V*I*X/z
agian V/Z=I
so Q=I(sqr)X
Since there is no any power loss when current flows through
the pure inductor or capacitor, but the energy is stored in
the form of magnetic field(in inductor) or static field (in
capacitor). So the reactive power is the power used for
magnetizing or is stored in capacitor in the form of static
field.

Answer / saad

Active power
Which iz doing the real work lighting heating etc
Reactive power
Which iz used for the magnetizing of motors,transformers
and generators coils.
active power iz use ful but with out reactive power u never
magnetize any motor transformer or generator u can just
only improve the power factor to reduce ur loss.
KVA * PF = KW
for example
100 * 1 = 100 KW
IF pf 0.8
100*.8= 80KW

Answer / d

D

Answer / vikas jaiswal

1. Power is an instantaneous quantity while energy has a
time component.
2. Energy predictably accumulates as power remains constant.
3. Energy is the sum accumulation of power whether it
remains constant or
varies.

Answer / nithya

reactive power is actually a useful power,which is used for
boosting up of voltages,it is the stored energy...
(capacitors),injection of reactive power is necessary at
some cases.

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