A.C. power supply voltage amplitude questions

[bluesteels]

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

 

[Orodruin]

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?

 

[Steve4Physics]

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

 

[bluesteels]

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

they didnt give me time?

 

[bluesteels]

What do you think the answer to (b) should be?

i know that it zero cause i look it up but idk why

 

[Orodruin]

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?

 

[Steve4Physics]

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!