Electronics - Capacitors - Discussion
Discussion Forum : Capacitors - General Questions (Q.No. 4)
4.
What is the reactive power in the given circuit?
0 VAR
691 
VAR
VAR44.23 mVAR
1.45 kVAR
Discussion:
36 comments Page 1 of 4.
KIRAN V said:
5 years ago
Given : F = 5 kHz; C = 0.22F
Where XC = CAPACITIVE LOAD.
XC = 1/ (2 * π * F * C).
XC = 1 / (6.28 * 5 * 103 * 0.022 * 10-6)
XC = 1 / 0.6908 * 10-3
XC = 1.4475 * 103 = 1447.5Ω.
P = V * I.
P = V2 / R or P = V2 / XC.
Here:
P = V2/XC.
P = 64 V / 1447.5,
P = 0.04421 Var.
P = 44.21 m Var.
Where XC = CAPACITIVE LOAD.
XC = 1/ (2 * π * F * C).
XC = 1 / (6.28 * 5 * 103 * 0.022 * 10-6)
XC = 1 / 0.6908 * 10-3
XC = 1.4475 * 103 = 1447.5Ω.
P = V * I.
P = V2 / R or P = V2 / XC.
Here:
P = V2/XC.
P = 64 V / 1447.5,
P = 0.04421 Var.
P = 44.21 m Var.
(3)
Rasika chougale said:
6 years ago
Good discussion, thanks everyone for explaining it.
(1)
Pavan Kumar said:
1 decade ago
Reactive Power is the power which is lost in the circuit and hence not delivered to the Load.
(1)
Krishna said:
1 decade ago
Reason behind sending back is because there is no dissipative path (load). In ideal case capacitor cannot dissipate.
Apparent power is pure resistive power whereas reactive power comes into picture because of capacitive reactance in the circuit.
P = v^2/R but now it is v^2/Z where z = R+Xc (Xc=1/2*pi*f*c)here R = 0 ideal case.
Xc=1/2*pi*f*c.
= 1/6.28*5000*0.022*10^-6.
= 1/31400*0.022*10^-6.
= 1447.59.
P = R^2/Xc = 64/1447.59 = 0.0442W = 44.21mW.
Apparent power is pure resistive power whereas reactive power comes into picture because of capacitive reactance in the circuit.
P = v^2/R but now it is v^2/Z where z = R+Xc (Xc=1/2*pi*f*c)here R = 0 ideal case.
Xc=1/2*pi*f*c.
= 1/6.28*5000*0.022*10^-6.
= 1/31400*0.022*10^-6.
= 1447.59.
P = R^2/Xc = 64/1447.59 = 0.0442W = 44.21mW.
Makkk said:
1 decade ago
What is the reason behind sending the power to source back?
Shashi said:
1 decade ago
Power reactive capacitance's formula is "P = V^2/Xc".
but now we don't know What is the Xc(Capacitance reactance)so first we should find Xc.
Xc = 1/2*pi*F*C.
Xc = 1446.86 ohm.
P = V^2/Xc.
= 8^2/1446.86.
= 64/1446.86.
= 0.4423 VAR.
= 44.23 mVAR.
but now we don't know What is the Xc(Capacitance reactance)so first we should find Xc.
Xc = 1/2*pi*F*C.
Xc = 1446.86 ohm.
P = V^2/Xc.
= 8^2/1446.86.
= 64/1446.86.
= 0.4423 VAR.
= 44.23 mVAR.
Gomathi said:
1 decade ago
Why they use the unit VAR (IN ANS). If it's one of the unit of mean where we use?
Rachna said:
1 decade ago
How the problem can be solve?
Kiran said:
1 decade ago
VAR - Volt Ampere Reactance (Units of reactive power).
Siva said:
1 decade ago
In our home we see 230 v whether it is RMRS value or anything.
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