Q :In synthesising a square wave using Fourier synthesis with four frequencies,
ID: 2079558 • Letter: Q
Question
Q :In synthesising a square wave using Fourier synthesis with four frequencies, why would we be unable to obtain a perfect square wave?
because it is not possible to add sinusoidal signals
because the synthesis was performed in the time domain
because amplitude errors in the signal generator would make the peaks rounded rather than flat
because four frequencies are not enough
Q : Suppose a signal generator can produce only square waves and saw-tooth waves. To obtain a wave as close as possible to a sine wave one might start with a square wave and filter it. What kind of filter should you use?
a notch filter
a band pass filter
a low pass filter
a high pass filter
a.because it is not possible to add sinusoidal signals
b.because the synthesis was performed in the time domain
c.because amplitude errors in the signal generator would make the peaks rounded rather than flat
d.because four frequencies are not enough
Explanation / Answer
Q: In synthesising a square wave using Fourier synthesis with four frequencies, why would we be unable to obtain a perfect square wave?
Synthesising is the process of generating a pure wave from a radio or musical signal by adjusting the amplitudes and phases of adding them properly together. But for this process we have to know the harmonics contents in the signal beforehand by applying Fourier analysis.
In order to synthesising a signal to its original state we want high peak amplitudes in a very short time. For this we are going to add a sinusoidal wave of share pulses of in short period of time. Which means we need a large amplitude wave at very high frequencies.
In this question we had gave only 4 frequency so it is not sufficient to produce a perfect square. We need high frequencies.
So Option D is the answer.
Q: Suppose a signal generator can produce only square waves and saw-tooth waves. To obtain a wave as close as possible to a sine wave one might start with a square wave and filter it. What kind of filter should you use?
To obtain a wave as close as possible to sine wave from a square wave we use 2nd order LOW PASS filter made up of inductor in series with the ac supply and capacitor to neutral and a resistor is places in series with the inductor. The resistor is placed to prevent the high peak voltages and to keep the Q of the circuit low.
So option C is the answer.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.