# Electronics - Alternating Current and Voltage - Discussion

Discussion Forum : Alternating Current and Voltage - General Questions (Q.No. 5)

5.

A half-cycle average voltage of 12 V is equal to what rms voltage?

Discussion:

24 comments Page 2 of 3.
KIRAN V said:
8 years ago

Given;

V avg = 12 V.

Formula taken w.r.f to Full wave rectifier.

Vavg = 2*V max / pi.

Vmax = (V avg * 3.14)/2.

Vmax = (12 * 3.14)/2.

Vmax = 18.84 V.

Vrms = V max /sq.root of (2).

Vrms = 18.84 /1.414.

Vrms = 13.323 V.

V avg = 12 V.

Formula taken w.r.f to Full wave rectifier.

Vavg = 2*V max / pi.

Vmax = (V avg * 3.14)/2.

Vmax = (12 * 3.14)/2.

Vmax = 18.84 V.

Vrms = V max /sq.root of (2).

Vrms = 18.84 /1.414.

Vrms = 13.323 V.

Pawan said:
7 years ago

It is, 18.84.

Rahul yadav said:
7 years ago

Yes, you are correct @Pawn.

Manish yadav said:
7 years ago

We are not use half wave formula because in electrical method also use full wave formula because in case of electrical we are use in wark 5volt minimum value and more than,

5volt <12volt. So we are useful wave formula.

Iavg.=12volt,

Im=12*3.14÷2=18.84

Irms=18.84÷1.41=13.36.

5volt <12volt. So we are useful wave formula.

Iavg.=12volt,

Im=12*3.14÷2=18.84

Irms=18.84÷1.41=13.36.

Lemjr said:
6 years ago

Here, Irms=peak value(Io)/1.41.

Shadan said:
6 years ago

Half Cycle means Half cycle flow in output so it is a half wave rectifier

So avverage voltage of half wave rectifier is =Vm/π.

So Vm =3.14*12,

Vm=26.64,

So rms value of HALF wave is Vm/2,

So 26.64/2=13.33.

So avverage voltage of half wave rectifier is =Vm/π.

So Vm =3.14*12,

Vm=26.64,

So rms value of HALF wave is Vm/2,

So 26.64/2=13.33.

Shadan said:
6 years ago

If we talk a Avverage voltage of a complete sine wave then it is 0

So we need to Take Avvg Voltage =0.637*Vm.

Vm = 18.84,

RMS=Vm/√2.

18.84/1.414,

=13.33.

So we need to Take Avvg Voltage =0.637*Vm.

Vm = 18.84,

RMS=Vm/√2.

18.84/1.414,

=13.33.

Whis said:
5 years ago

The answer must be 18.85.

Let me explain,

For half wave rectifier:

Vave = Vpk/π

12v = Vpk / 3.14,

12*3.14 = Vpk,

Vpk = 37.699V.

To get rms of half wave rectifer:

vrms(halfwave) = vpk/2.

Vrms(half wave) = 37.699/2.

Vrms = 18.85V.

Let me explain,

For half wave rectifier:

Vave = Vpk/π

12v = Vpk / 3.14,

12*3.14 = Vpk,

Vpk = 37.699V.

To get rms of half wave rectifer:

vrms(halfwave) = vpk/2.

Vrms(half wave) = 37.699/2.

Vrms = 18.85V.

Muhammad Nouman said:
5 years ago

Answer is 18.84v.

Explanation:

For Half Wave Cycle Vrms = Vm/2.

and Vm = Vavg x π where π = 3.14 and Vavg = 12v,

So Vm = 12 x 3.14 = 37.68.

and

Vrms = Vm/2 = 37.68/2 = 18.84v.

Vrms = 18.84v.

Explanation:

For Half Wave Cycle Vrms = Vm/2.

and Vm = Vavg x π where π = 3.14 and Vavg = 12v,

So Vm = 12 x 3.14 = 37.68.

and

Vrms = Vm/2 = 37.68/2 = 18.84v.

Vrms = 18.84v.

(1)

KIRAN V said:
4 years ago

Vrms = Vpeak x .707.

Vrms = 1.11 x Vavg.

Vpeak = 1.414 x Vrms.

Vavg = .637 x Vpeak.

Vrms = 1.11 x Vavg.

Vpeak = 1.414 x Vrms.

Vavg = .637 x Vpeak.

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