Expected power of a square wave

[Tjvelcro]

Homework Statement

What is the expected power of the first three frequency components of a square wave with an amplitude of 0.2V?

Homework Equations

None that I know of :(

The Attempt at a Solution

I'm not sure where to start with this since it seems to give me so little information. I think I may have to use V(rms) but I'm not sure. Any help or hints would be appeciated.

Tjvelcro

 

[rootX]

Do you know equation of power for periodic waves?

 

[Tjvelcro]

No, I am not sure what that equation is... tried to look in my book but cannot find it.

 

[rootX]

$$\frac{1}{T}\int_{0}^{T}|x(t)|^2\,dt$$

Above is the power equation.

However, it seems like you are attempting to finding power contained in first three frequency components of square wave. I only read the title thought you want power of square wave. I would suggest you to look into .. Parseval's Theorem (http://engnet.anu.edu.au/DEcourses/engn2228/Lectures/Lecture15.pdf slide 11).

 

[DeeNos]

,

I can provide some guidance on how to approach this problem. The first step would be to define the power of a signal. In this case, we are dealing with an electrical signal, so we can use the equation P = V^2/R, where P is power, V is voltage, and R is resistance.

Next, we can look at the formula for a square wave, which is a periodic waveform with a constant amplitude. The square wave can be represented by a series of sine waves with different frequencies. The first three frequency components of a square wave are its fundamental frequency, twice the fundamental frequency, and three times the fundamental frequency.

To calculate the power of each frequency component, we can use the formula P = V^2/R, where V is the amplitude of the square wave (0.2V) and R is the resistance of the circuit. Since we do not have information about the resistance, we can assume a standard value of 1 ohm for simplicity.

So, the expected power of the first three frequency components would be:

- Fundamental frequency: P = (0.2V)^2/1 ohm = 0.04W
- Twice the fundamental frequency: P = (0.2V)^2/1 ohm = 0.04W
- Three times the fundamental frequency: P = (0.2V)^2/1 ohm = 0.04W

Therefore, the total expected power of the first three frequency components of a square wave with an amplitude of 0.2V would be 0.12W.

I hope this helps! Remember, when dealing with signals, it is important to define the parameters and equations that are relevant to the problem. Good luck with your homework!