1-Phase CircuitsAlternating CurrentBasic ConceptsQuestions - Answers

AC Voltage at Home is 230V but its Equation is v = Vm Sin θ. Explain?

Domestic AC Voltage at Home is 230V but its Equation is v = Vm Sin θ. Explain the Difference?

Our homes are supplied with sinusoidal voltage whose equation should be (v = Vm Sin θ). But we always say that AC voltage at home is 230V. How do you explain this difference?

The domestic single phase AC supply is 230V, 50Hz (in EU) or 110V 60Hz in US. It is the RMS or effective value. It means that alternating voltage available has the same heating effect as 230V DC. The equation of this alternating voltage:

v = Vm Sin θ

v = Vm Sin ωt ….. (θ = ωt)

v = 230VRMS x √2 Sin 2π x 50 t ….. [Putting Vm = √2 VRMS and ω = 2π]

v = 230VRMS x √2 Sin 314 t Volts

In short, the figure of 110V or 230V is not the exact value of sinusoidal voltage at our homes supplied by the power house. But it is the exact value of RMS voltage i.e. we get the amount of AC voltage having the same effect of 110V DC or 230VDC respectively.

AC Voltage at Home is 230V but its Equation is v = Vm Sin θ. Explain the Difference?

Keep in mind that the 230V AC in domestic supply has the peak value of 325VP (Peak Voltage) or 650VP-P (Peak to Peak Voltage) and 207VAVG (Average Voltage).

Same is the case for 110V AC which peak voltage, peak to peak voltage and average voltage are 155VP, 310VP-P, 99VAVG respectively by using the RMS value calculator and peak voltage calculator.

Related Posts:

Electrical Technology

All about Electrical and Electronic Engineering & Technology. Join us on WhatsApp at Electrical Technology Official Channel, to receive the latest content, articles, and updates. You can also like and follow our social media networks below, or subscribe with your email to receive premium engineering articles in your mailbox.


  1. Average value of Alternating Current means average value of whole period T (in Europe T = 0,02 [s]) and RMS value is an amplitude of current divided by square root of 2 ?

    Coz AC Current and Voltage has Frequency..When EMF induce in AC alternator , According to AC concept ( DC has not frequency while AC Has..) There Will be frequency…. And the concept of 60 and 50 Hz…that where it came from….? remember the famous formula Ns = 120f/P … or f = 120 /(PxNs).

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button