# Electronics - RL Circuits - Discussion

Discussion Forum : RL Circuits - General Questions (Q.No. 3)
3.
What is the true power of a 24 Vac parallel RL circuit when R = 45 and XL = 1100 ?
313.45 W
12.8 W
44.96 W
22.3 W
Explanation:
No answer description is available. Let's discuss.
Discussion:
12 comments Page 1 of 2.

Pawan said:   5 years ago
Why is inductive reactance not considered here?

Priti said:   6 years ago
Ir=24/45(voltage equal in parallel).
Then,
Real power =Ir^2 * 45 = 12.8.

Rajan said:   6 years ago
Another way is total I * V.
There is a power dissipated in the resistor and also low lost in Inductor.
So both need to be considered !

In parallel circuit Total current It= IL +Ir but since they are not in the same phase so cannot plus directly.

It^2 = IL^2 + Ir^2.

Ir = V/R =24/45 = 0.533.
IL = V/Xl =24/1100 = 0.0218.

It = sqr(IL^2 +Ir^2) = sqr(0.5333*0.5333 +0.02182*0.02182) = 0.53345.

It = 0.53345 ampere.

Power = VIt = 24 * 0.5334 = 12.80 (more accurate).

Sudhi. said:   8 years ago
If there is no losses in the inductor it is simple. This means no equivalent series or parallel are. Use 2pi x f x L to get the reactance, and then the current by ohms law.

There is no power dissipated. Current is drawn but it recirculates without any heating. The inductor charges and discharges.

ARUN said:   9 years ago
Impedance z = 44.9 ohm.

I = V/Z = 0.534 A.

TRUE POWER = V*I*COS(PHI)=12.78 VOLT.

PHI = TAN inv(R/Xl) = 2.34.

Nasim said:   10 years ago
Please say why there is no power dissipation in the inductor?

Lochana.vyas said:   10 years ago
As they said only true power so inductance value will not be there and only purely resistive load is used:-.

V^2/R = (24) ^2/45 = 12.8W.

Sindhu priya said:   1 decade ago
I=V/R=24/45=0.533
P=VI=24*0.533=12.8
(2)

C.P. BORKAR said:   1 decade ago
First calculate

I=V/R =24/45 = O.533

THEN P=VI
P=24*0.533
P=12.8