Answer / ran145

In an AC circuit whose impedance consists of reactance as
well as resistance, the voltage and current are not in phase.
when there is reactance in an AC circuit, the product Erms
Irms is greater than the true power. The excess is called
reactive power.

In DC impedance is a pure resistance hence the voltage and
current are in phase which produces true power
i.e.P=Erms*Irms . hence there is no reactive power in DC.

Answer / k.prakashchandra

Dc produces a steady magnetic field unlike AC

Answer / sp

in case of dc supply the frequency is zero

Answer / srikanth

active power is VI COSΦ and reactive power is VI SINΦ.In dc circuits v and I will be in phase.that is Φ=0. so COSΦ=1 and SINΦ=0.so no reactive power.

Answer / haydad ahmad

There is no reactive power in dc circuits because reactive power is produce due to phase difference in ac circuits but which is not in dc circuits .In dc circuits V and I lies at straight line so reactive power in dc circuits is zero.

Answer / rohan joshi

In D.C phase angle is zero. hence power factor is 1.
we know that reactive power is Q=VISin(angle), so its zero.

Answer / sethar12

Is the impedance in a DC motor with magnetic field in its
winding pure resistive? Is the current not consumed in this
inductive load?

what is meant by phase transformation ratio in induction motors?

2 Answers  

How is earthing done in Aerospace applications such as Flights and spaceships..?

1 Answers  

can u give me a brief idea about power line carrier communication ??

0 Answers  

what is the maximum current carrying capacity of a 95 sqmm cupper under ground cable laid partialy in land and partialy in ground?

4 Answers  

oltc of a transformer, how it works? and what are the equipment consist of describe briefly?

0 Answers  

What are the protective devices in a DC/AC motor starter?

1 Answers   CTS,

While DG is on Load? we can start the capacitor bank?

3 Answers   Inorbit,

why we use the fuse in only one wire? althrough in ac current the current flows in both directions. why the neutral wire can be taken half the magnitude of phase wire while same current returns from neutral wire?

2 Answers   Bhel,

in a dc shunt motor what happens if motor takes high current,no speed

2 Answers  

1. The DC generaror,s induced output emf is connected with a DC motor(as load). when increasing the load of the motor by using brake drum or any way. what are the parameters will changes in both motor and generator(voltage, current, resistance, frequency, speed, torque, power, flux etc...) 2. Similarly for AC generator and AC motor 3. similarly if using DC batteries instead of DC generator, What happens?

0 Answers   IBM, Kirloskar,

what happen "when Dyn11 is parallel operation with Dyn1"?

9 Answers  

The unit of resistivity is:(a) ohms(b) ohm millimetre(c) ohm metre(d) ohm/metre

4 Answers