A.C. power supply voltage amplitude questions

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Homework Help Overview

The discussion revolves around understanding the voltage characteristics of an alternating current (AC) power supply, specifically focusing on the root-mean-square (Vrms) and average potential differences (Vav) between the terminals. Participants are examining why the average potential difference is considered zero in this context.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are questioning the reasoning behind the average potential difference being zero, with some referencing the sinusoidal nature of the voltage graph. There are inquiries about the implications of not having time data and how it affects the understanding of the average voltage over a complete cycle.

Discussion Status

There is ongoing exploration of the concept, with participants sharing their thoughts and seeking clarification on the average voltage. Some have provided insights into the graphical representation of AC voltage, while others are prompted to think critically about their assumptions and reasoning without relying on external sources.

Contextual Notes

Participants note the absence of time data in the problem statement, which may affect their analysis. There is also a suggestion to consider the average voltage over a complete cycle, indicating a potential area of confusion regarding the definitions involved.

bluesteels
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Homework Statement
The voltage across the terminals of an ac power supply varies with
time. The voltage amplitude is V = 45.0 V. What
are (a) the root-mean-square potential difference Vrms and (b) the average
potential difference Vav between the two terminals of the power supply?
Relevant Equations
Vmax= square root 2*Vrms
I know that the answer for A is 31.82. But when i look up B why is it zero? can someone explain please

thank you
 
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bluesteels said:
Homework Statement:: The voltage across the terminals of an ac power supply varies with
time. The voltage amplitude is V = 45.0 V. What
are (a) the root-mean-square potential difference Vrms and (b) the average
potential difference Vav between the two terminals of the power supply?
Relevant Equations:: Vmax= square root 2*Vrms

But when i look up B why is it zero? can someone explain please
What do you think the answer to (b) should be?
 
bluesteels said:
Homework Statement:: The voltage across the terminals of an ac power supply varies with
time. The voltage amplitude is V = 45.0 V. What
are (a) the root-mean-square potential difference Vrms and (b) the average
potential difference Vav between the two terminals of the power supply?
Relevant Equations:: Vmax= square root 2*Vrms

I know that the answer for A is 31.82. But when i look up B why is it zero? can someone explain please
Look at a graph of (sinusoidal) alternating voltage vs. time. Can you use the graph to explain why the average is zero?
https://www.teamwavelength.com/download/alternating-1024x597.png
 
Orodruin said:
What do you think the answer to (b) should be?
i know that it zero cause i look it up but idk why
 
bluesteels said:
i know that it zero cause i look it up but idk why
No, what do you think it should be without looking it up. Without referring to any authority, what do you think it should be?
 
bluesteels said:
they didnt give me time?
Another way to ask the question is:
What is the average voltage over each complete cycle?​
Does that help?

Also, you might want to reply to @Orodruin's Post #6!
 

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