How to find the root mean square voltage of a Sine wave? [closed]

-2

$begingroup$

I'm giving a code in matlab and have to answer some questions, I'm having some doubts on some of the questions I've done.

Original code:

%Paremeter setting

A = 1; %Amplitude

f = 1; %frequency

P = 0; %Phase

time = 1.5; %time duration

N = 1000; %Sampling number

t = 0:time/(N-1):time;

%Generate sin wave

s = A*sin(2*pift+P);

%Draw figure

plot(t,s)

grid on

xlabel('Time')

ylabel('Amplitude')

Questions:


1. Run the code and plot the figure; what is the period of the output signal?

2. Change the A = 0.5, then run the code; what is the root mean square voltage of the signal?

3. Change the f = 2, then run the code; what is the period of the output signal?

4. Change the P=pi/4, then run the code; what is the value of the single at time = 0?

My answers:



1. one second



2. This is what's confusing me: The peak is o.707, do I divide this by 2 or $sqrt2$?



3. 0.5 seconds



4. 0.707



I'm having problems with question 2, but are the other answers correct?

algebra-precalculus matlab

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asked Jan 26 at 5:08

Larvitar Larvitar

165

$endgroup$

closed as off-topic by José Carlos Santos, Shailesh, NCh, Cesareo, Gibbs Jan 28 at 0:23

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question is not about mathematics, within the scope defined in the help center." – NCh, Cesareo, Gibbs

If this question can be reworded to fit the rules in the help center, please edit the question.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Root mean square= $sqrt {dfrac {x_1^2+x_2^2+ldots + x_{n-1}^2+x_n^2}n}$
  $endgroup$
  – Mohammad Zuhair Khan
  Jan 26 at 5:13
  

  
  
  
  

add a comment | 

-2

$begingroup$

I'm giving a code in matlab and have to answer some questions, I'm having some doubts on some of the questions I've done.

Original code:

%Paremeter setting

A = 1; %Amplitude

f = 1; %frequency

P = 0; %Phase

time = 1.5; %time duration

N = 1000; %Sampling number

t = 0:time/(N-1):time;

%Generate sin wave

s = A*sin(2*pift+P);

%Draw figure

plot(t,s)

grid on

xlabel('Time')

ylabel('Amplitude')

Questions:


1. Run the code and plot the figure; what is the period of the output signal?

2. Change the A = 0.5, then run the code; what is the root mean square voltage of the signal?

3. Change the f = 2, then run the code; what is the period of the output signal?

4. Change the P=pi/4, then run the code; what is the value of the single at time = 0?

My answers:



1. one second



2. This is what's confusing me: The peak is o.707, do I divide this by 2 or $sqrt2$?



3. 0.5 seconds



4. 0.707



I'm having problems with question 2, but are the other answers correct?

algebra-precalculus matlab

share|cite|improve this question

asked Jan 26 at 5:08

Larvitar Larvitar

165

$endgroup$

closed as off-topic by José Carlos Santos, Shailesh, NCh, Cesareo, Gibbs Jan 28 at 0:23

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question is not about mathematics, within the scope defined in the help center." – NCh, Cesareo, Gibbs

If this question can be reworded to fit the rules in the help center, please edit the question.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Root mean square= $sqrt {dfrac {x_1^2+x_2^2+ldots + x_{n-1}^2+x_n^2}n}$
  $endgroup$
  – Mohammad Zuhair Khan
  Jan 26 at 5:13
  

  
  
  
  

add a comment | 

-2

-2

-2

$begingroup$

I'm giving a code in matlab and have to answer some questions, I'm having some doubts on some of the questions I've done.

Original code:

%Paremeter setting

A = 1; %Amplitude

f = 1; %frequency

P = 0; %Phase

time = 1.5; %time duration

N = 1000; %Sampling number

t = 0:time/(N-1):time;

%Generate sin wave

s = A*sin(2*pift+P);

%Draw figure

plot(t,s)

grid on

xlabel('Time')

ylabel('Amplitude')

Questions:


1. Run the code and plot the figure; what is the period of the output signal?

2. Change the A = 0.5, then run the code; what is the root mean square voltage of the signal?

3. Change the f = 2, then run the code; what is the period of the output signal?

4. Change the P=pi/4, then run the code; what is the value of the single at time = 0?

My answers:



1. one second



2. This is what's confusing me: The peak is o.707, do I divide this by 2 or $sqrt2$?



3. 0.5 seconds



4. 0.707



I'm having problems with question 2, but are the other answers correct?

algebra-precalculus matlab

share|cite|improve this question

asked Jan 26 at 5:08

Larvitar Larvitar

165

$endgroup$

I'm giving a code in matlab and have to answer some questions, I'm having some doubts on some of the questions I've done.

Original code:

%Paremeter setting

A = 1; %Amplitude

f = 1; %frequency

P = 0; %Phase

time = 1.5; %time duration

N = 1000; %Sampling number

t = 0:time/(N-1):time;

%Generate sin wave

s = A*sin(2*pift+P);

%Draw figure

plot(t,s)

grid on

xlabel('Time')

ylabel('Amplitude')

Questions:


1. Run the code and plot the figure; what is the period of the output signal?

2. Change the A = 0.5, then run the code; what is the root mean square voltage of the signal?

3. Change the f = 2, then run the code; what is the period of the output signal?

4. Change the P=pi/4, then run the code; what is the value of the single at time = 0?

My answers:



1. one second



2. This is what's confusing me: The peak is o.707, do I divide this by 2 or $sqrt2$?



3. 0.5 seconds



4. 0.707



I'm having problems with question 2, but are the other answers correct?

algebra-precalculus matlab

algebra-precalculus matlab

share|cite|improve this question

asked Jan 26 at 5:08

Larvitar Larvitar

165

share|cite|improve this question

asked Jan 26 at 5:08

Larvitar Larvitar

165

share|cite|improve this question

share|cite|improve this question

asked Jan 26 at 5:08

Larvitar Larvitar

165

asked Jan 26 at 5:08

Larvitar Larvitar

165

asked Jan 26 at 5:08

Larvitar Larvitar

165

165

closed as off-topic by José Carlos Santos, Shailesh, NCh, Cesareo, Gibbs Jan 28 at 0:23

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question is not about mathematics, within the scope defined in the help center." – NCh, Cesareo, Gibbs

If this question can be reworded to fit the rules in the help center, please edit the question.

closed as off-topic by José Carlos Santos, Shailesh, NCh, Cesareo, Gibbs Jan 28 at 0:23

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question is not about mathematics, within the scope defined in the help center." – NCh, Cesareo, Gibbs

If this question can be reworded to fit the rules in the help center, please edit the question.

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Root mean square= $sqrt {dfrac {x_1^2+x_2^2+ldots + x_{n-1}^2+x_n^2}n}$
  $endgroup$
  – Mohammad Zuhair Khan
  Jan 26 at 5:13
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  Root mean square= $sqrt {dfrac {x_1^2+x_2^2+ldots + x_{n-1}^2+x_n^2}n}$
  $endgroup$
  – Mohammad Zuhair Khan
  Jan 26 at 5:13
  

  
  
  
  

$begingroup$
Root mean square= $sqrt {dfrac {x_1^2+x_2^2+ldots + x_{n-1}^2+x_n^2}n}$
$endgroup$
– Mohammad Zuhair Khan
Jan 26 at 5:13

$begingroup$
Root mean square= $sqrt {dfrac {x_1^2+x_2^2+ldots + x_{n-1}^2+x_n^2}n}$
$endgroup$
– Mohammad Zuhair Khan
Jan 26 at 5:13

add a comment | 

1 Answer
1

active

oldest

votes

1

$begingroup$

For a sine wave (assumed symmetric around zero) the rms level is $frac {sqrt 2}2$ of the peak level. This is because the average value of $sin^2$ is $frac 12$, which you can show by integration.

share|cite|improve this answer

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  So I multiply 0.707 by ( (sqrt(2))/2 )?
  $endgroup$
  – Larvitar
  Jan 26 at 7:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  That is correct.
  $endgroup$
  – Ross Millikan
  Jan 26 at 15:17
  

  
  
  
  

add a comment | 

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

active

oldest

votes

active

oldest

votes

1

$begingroup$

For a sine wave (assumed symmetric around zero) the rms level is $frac {sqrt 2}2$ of the peak level. This is because the average value of $sin^2$ is $frac 12$, which you can show by integration.

share|cite|improve this answer

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  So I multiply 0.707 by ( (sqrt(2))/2 )?
  $endgroup$
  – Larvitar
  Jan 26 at 7:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  That is correct.
  $endgroup$
  – Ross Millikan
  Jan 26 at 15:17
  

  
  
  
  

add a comment | 

1

$begingroup$

For a sine wave (assumed symmetric around zero) the rms level is $frac {sqrt 2}2$ of the peak level. This is because the average value of $sin^2$ is $frac 12$, which you can show by integration.

share|cite|improve this answer

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

$endgroup$

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  So I multiply 0.707 by ( (sqrt(2))/2 )?
  $endgroup$
  – Larvitar
  Jan 26 at 7:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  That is correct.
  $endgroup$
  – Ross Millikan
  Jan 26 at 15:17
  

  
  
  
  

add a comment | 

1

1

1

$begingroup$

For a sine wave (assumed symmetric around zero) the rms level is $frac {sqrt 2}2$ of the peak level. This is because the average value of $sin^2$ is $frac 12$, which you can show by integration.

share|cite|improve this answer

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

$endgroup$

For a sine wave (assumed symmetric around zero) the rms level is $frac {sqrt 2}2$ of the peak level. This is because the average value of $sin^2$ is $frac 12$, which you can show by integration.

share|cite|improve this answer

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

share|cite|improve this answer

share|cite|improve this answer

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

answered Jan 26 at 6:24

Ross MillikanRoss Millikan

300k24200374

300k24200374

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  So I multiply 0.707 by ( (sqrt(2))/2 )?
  $endgroup$
  – Larvitar
  Jan 26 at 7:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  That is correct.
  $endgroup$
  – Ross Millikan
  Jan 26 at 15:17
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  So I multiply 0.707 by ( (sqrt(2))/2 )?
  $endgroup$
  – Larvitar
  Jan 26 at 7:25
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  $begingroup$
  That is correct.
  $endgroup$
  – Ross Millikan
  Jan 26 at 15:17
  

  
  
  
  

$begingroup$
So I multiply 0.707 by ( (sqrt(2))/2 )?
$endgroup$
– Larvitar
Jan 26 at 7:25

$begingroup$
So I multiply 0.707 by ( (sqrt(2))/2 )?
$endgroup$
– Larvitar
Jan 26 at 7:25

$begingroup$
That is correct.
$endgroup$
– Ross Millikan
Jan 26 at 15:17

$begingroup$
That is correct.
$endgroup$
– Ross Millikan
Jan 26 at 15:17

add a comment | 

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