AC Voltage at Point X on Wire: Positive and Negative Half Cycle

Click For Summary

Discussion Overview

The discussion revolves around the behavior of AC voltage at a specific point (Point X) on a wire during the positive and negative half-cycles of a sinusoidal AC supply. Participants explore the implications of distance from the source, the nature of the voltage waveform, and the direction of current flow.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant asks about the potential at Point X during both half-cycles of a sinusoidal AC supply and the direction of current.
  • Another participant emphasizes the need for time and a graph of the AC source to fully understand the situation.
  • A suggestion is made to draw a sketch of an AC voltage source driving a resistor divider to visualize the AC waveforms.
  • It is proposed that the voltage at Point X will resemble the source voltage but will be slightly delayed due to the finite speed of voltage transmission, assuming the wire is of reasonable length.
  • Discussion includes the concept of rms values of AC voltages, with a participant explaining the relationship between rms voltage and peak voltage for a sine wave.
  • Another participant notes that the formula for calculating rms voltage applies specifically to sine waves, while acknowledging that AC waveforms can take other forms, such as sawtooth waves.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the voltage waveform and the applicability of certain formulas, indicating that multiple competing perspectives remain without a consensus on the specifics of the AC voltage behavior at Point X.

Contextual Notes

Limitations include the assumption of wire length affecting voltage transmission and the specific conditions under which the rms voltage formula is applicable, which may not hold for non-sinusoidal waveforms.

amaresh92
Messages
163
Reaction score
0
greetings,

consider a wire which is subjected to AC supply.now consider a point X anywhere on wire.
now what will be the potential of that point during the positive and negative halfcycle of sinusoidal AC?what will be the direction of current?
thanks
 
Engineering news on Phys.org
not only you need X, you also need time. then you need the graph of the ac source
 
amaresh92 said:
greetings,

consider a wire which is subjected to AC supply.now consider a point X anywhere on wire.
now what will be the potential of that point during the positive and negative halfcycle of sinusoidal AC?what will be the direction of current?
thanks

What do you think? Why don't you draw a sketch of an AC voltage source driving a resistor divider. Sketch the AC waveforms -- what do they show?
 
An easy way to answer your question is to consider that at the point some distance from the source, the voltage (potential) will be exactly like the source voltage, just delayed a tiny bit in time to account for the finite speed of the voltage transmission...assuming the wire is a few inches or feet not tens of thousands of miles...so you have answered your own question in your post...
 
berkeman said:
What do you think? Why don't you draw a sketch of an AC voltage source driving a resistor divider. Sketch the AC waveforms -- what do they show?


what kind of thing the voltage?
 
Last edited by a moderator:
You can check the rms values of AC voltages. Suppose if you have 220Vrms than it means your AC waveform is a sine wave having positive peak of 311 volts and negative peak of 311 volts. This means peak to peak voltages are 311+311=622 volts.
Peak Voltage = RMS Voltage x square root of 2
Thanks
 
ssana said:
Peak Voltage = RMS Voltage x square root of 2
Thanks

Only on a sine wave.
 
Usually sine wave is generated from the generator coil. The alternate wave is not necessary a sine wave. It can be sawtooth wave or any alternate cycles. The above mentioned formula to calculate rms voltage is for the sine wave.
 

Similar threads

  • · Replies 21 ·
Replies
21
Views
5K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 12 ·
Replies
12
Views
17K
Replies
12
Views
2K
Replies
2
Views
3K