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.
                
                        Manish yadav said: 
                         
                        8 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.
                        Rahul yadav said: 
                         
                        9 years ago
                
                Yes, you are correct @Pawn.
                
                        Pawan said: 
                         
                        9 years ago
                
                It is, 18.84.
                
                        KIRAN V said: 
                         
                        9 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.
                        SAs said: 
                         
                        10 years ago
                
                For half cycle.
Effective voltage or RMS = 1.11*V average.
= 1.11*12 = 13.32 v.
                Effective voltage or RMS = 1.11*V average.
= 1.11*12 = 13.32 v.
                        Engineer Marc said: 
                         
                        1 decade ago
                
                This is wrong. If you use full wave formula:
Valve = 2Vpeak/3.1416 => 12 = 2Vpeak/3.14160 (Shift solve).
Vpeak = 18.8496 (full wave).
For full wave Vrms:
Vrms = Vpeak/sqrt 2 = 18.8496/sqrt 2 = 13.13 (Vrms for full wave).
The correct formula for half wave is:
Valve = Vpeak/3.1416 => 12 = Vpeak/3.1416 (Shift solve).
Vpeak = 37.6992.
For Vrms half wave its:
Vrms = Vpeak/2 => 37.6992/2 = 18.84.
                Valve = 2Vpeak/3.1416 => 12 = 2Vpeak/3.14160 (Shift solve).
Vpeak = 18.8496 (full wave).
For full wave Vrms:
Vrms = Vpeak/sqrt 2 = 18.8496/sqrt 2 = 13.13 (Vrms for full wave).
The correct formula for half wave is:
Valve = Vpeak/3.1416 => 12 = Vpeak/3.1416 (Shift solve).
Vpeak = 37.6992.
For Vrms half wave its:
Vrms = Vpeak/2 => 37.6992/2 = 18.84.
                        Vinod semwal said: 
                         
                        1 decade ago
                
                Vpick = pai* Vavrag/2.
Vpick = 3.14*12/2.
= 18.84.
Vrms = Vpick/1.414.
= 18.84/1.414.
= 13.33 V.
                Vpick = 3.14*12/2.
= 18.84.
Vrms = Vpick/1.414.
= 18.84/1.414.
= 13.33 V.
                        Stp said: 
                         
                        1 decade ago
                
                Form factor Kf = (rms value/half cycle average value).
Kf for sine wave 1.11.
rms value = 1.11X12= 13.33.
                Kf for sine wave 1.11.
rms value = 1.11X12= 13.33.
                        Sunday said: 
                         
                        1 decade ago
                
                Can same formula work for rms and half cycle.
                
                        Kaneez fatima said: 
                         
                        1 decade ago
                
                You all are applying formula for full cycle, but in question we asked to find rms for half cycle. If we apply formula for the half cycle answer may be wrong.
                Post your comments here:
 
            
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