The MATLAB program fft935.m uses the command Pxx = X.*conj(X)/(N/2) which computes
power spectral density at each frequency
both of these
energy in the x(t) at each frequency
The MATLAB program fft935.m uses the command X = fft(x,N) where ___ is the variable containing a bunch of complex numbers.
X
The MATLAB program fft935.m uses the command X = fft(x,N) where ___ is the function that performs the Fourier Transform.
fft
The MATLAB program fft935.m uses the command X = fft(x,N) where ___ is the number of values of x and X.
N
. The MATLAB program fft935.m uses the command X = fft(x,N) where ___ is the time-domain signal
x
Ex935 requires the MATLAB program fft935.m which performs an FFT. The number of lines of program code required for the FFT function is
1
Ex935 requires the MATLAB program fft935.m which computes and plots the Fourier Transform of x(t).
true
Ex935 requires the MATLAB program fft935.m implements the Fourier Transform using a specific implemention:
fft - Fast Fourier Transform
Ex935 requires the MATLAB program fft935.m which is also called a
script
Ex935 generates a time-domain signal where the signal-to-noise ratio is nearly
0.3
Ex935 generates a time-domain signal with 3 sinusoids and noise with a peak-to-peak amplitude of nearly
60
Ex935 generates a time-domain signal with 3 sinusoids with a peak-to-peak amplitude of nearly
16
Ex935 generates a time-domain signal with 3 sinusoids that have ____ frequencies and _____ amplitudes.
different, different
Ex935 generates a time-domain signal containing _____ values.
4096
Ex935 generates a time-domain signal containing _____.
noise or random numbers, which are the same thing
Ex935 generates a time-domain signal containing ____ sine components.
3
Ex935 is primarily about
the Fourier Transform
For a Bode phase of 85 degrees, and an input of A*sin(w*t), the output at that frequency would be
B*sin(w*t+85 deg)
For a Bode gain of -20 dB, and an input of 30sin(w*t), the output at that frequency would be
3sin(w*t+theta)
For a Bode gain of -20 dB, the system numeric gain at that frequency is
0.1
A Bode plot shows output and input sine wave ratios over a wide range of frequencies.
true
A Bode plot shows the sinusoidal output signal for a linear system relative to the sinusoidal input signal.
true
A high-pass Bode phase plot shows nearly _____ phase at low frequency and nearly ______ phase at high frequency.
90, 0
A high-pass Bode gain plot shows _____ gain at low frequency and ______ gain at high frequency.
low, high
The Bode phase plot is
phase in degrees vs frequency in rad/sec
The Bode gain plot is
gain in dB vs frequency in rad/sec
Both Bode plot gain and phase plots are ______ plots.
semilog
Both Bode plot gain and phase axes are
linear scales
In both Bode plot gain and phase axes, _____ axes are different in both plots.
vertical
The Bode plot frequency axis is a
log scale
The Bode plot frequency axis is the
horizontal axis and is the same for both plots
The bottom Bode plot is
system phase vs frequency
The top Bode plot is
system gain vs frequency
A Bode plot is
two plots
A Bode plot is a description of a
linear system
Vout/Vin = -R2/R1 is a number (e.g. -3), therefore Vout =
-3*Vin
Vout/Vin = -R2/R1 is a number and is also called the ____ of the inverting opamp configuration
gain
An ameteur mastake occurs in the audio portion of the video since KVL is mentioned, but KCL should have been stated.
t/f
true
The power-supply ground for the internal opamp circuit (not the noninverting input) is
not connected to the opamp
The non-inverting input (positive input port) is grounded in the inverting opamp configuration because
0 volts is desired at the inverting input.
The positive and negative supply voltages in the opamp video
are present but not shown
Negative in the inverting opamp transfer function (-R2/R1) means
both of these
negative input produces positive output voltage
positive input produces negative output voltage
The transfer function (Vout/Vin) of an inverting opamp configuration like in the video is
-Z2(s)/Z1(s)
The transfer function (Vout/Vin) of the inverting opamp configuration in the video is
-R2/R1
What does an opamp with negative feedback do? It makes the voltage at the negative input port the same as the voltage at the positive input port.
true if opamp limits of voltage and current are not exceeded
The ideal-opamp current (ma) to the signal-input ports is about
0
How many signal output ports does the opamp have?
1
The opamp has ____ power ports (voltage-supply inputs).
2
The opamp has ____ signal-input ports.
2
An opamp with a resitor in negative feedback and another resistor that is connected from the input signal to the negative input port is _____. The positive input port is grounded.
an inverting amplifier
The opamp with its many external configurations is one of the most useful electronic circuits.
t/f
true
A transfer function is a _______-domain concept.
complex-vaiable s
A transfer function is a ratio of two
s-domain signals (output divided by input)
A transfer function is a linear-system ____-domain I/O relationship for which input and output signals ______.
s, may be unknown
Voltage and current are common examples of ______ in ______ engineering.
signals, electrical
Position, velocity, acceleration, pressure, temperature, humidity are common examples of ____ in ____ engineering
signals, mechanical
Common electrical and mechanical signals
can be expressed in the time domain and the s-domain
The linear-system transfer function can be determined without knowing input or output signals.
t/f
true
The linear-system transfer function (TF) can be written without knowing input or output signals, and the TF = output/input.
t/f
true
TF1 and TF2 are in series. TF= combination of both. TF=
TF1*TF2
TF1 and TF2 are in parellel. TF= combination of both. TF=
TF1+TF2
TF1 is the forward TF. TF2 is the feedback TF in a _____ feedback path. The combination of both is TF=
negative, TF1/(1+TF1*TF2)
The TF=(s+a)/(s+b) has
one real pole at s=-b
The TF=25/(s^2+6s+25) = 25/( (s+3)^2 + 4^2 ) has
a pair of complex poles at s=-3+j4 and s=-3-j4
The TF=25/(s^2+6s+25) = 25/( (s+3)^2 + 4^2 ) is an example of
a 2nd-order TF
The TF=25/(s^2+6s+25) can also be written as TF=wn^2/(s^2 + 2*zeta*wn*s + wn^2)
t/f
true
In the TF=wn^2/(s^2 + 2*zeta*wn*s + wn^2), wn is
undamped natural frequency in rad/sec
In the TF=wn^2/(s^2 + 2*zeta*wn*s + wn^2), zeta is
damping ratio with no units
In the TF=25/(s^2+6s+25), the undamped natural frequency is _____ rad/sec.
5
In the TF=25/(s^2+6s+25), the damping ratio is
0.6
Damping ratio (zeta) and undamped natural frequency (wn) are ____-domain concepts.
s
Specific values of damping ratio (zeta) and undamped natural frequency (wn) ___ related to time-domain concepts.
are
4/0 is
infinity
-1.1E-15/0 is
negative infinity
The calculator reading (1.2E-14 to 1.2E-15) should be interpreted as
a value of zero due to roundoff at calculator limits
An electrical system with an infinite impedance
draws zero current and may have non-zero voltage across it, and KVL still applies to the loop.
Can a bunch of sine and cosine functions be added to approximate any function that is periodic or not periodic?
yes
Can a bunch of sine and cosine functions be added to make any periodic function?
yes
Can a bunch of sine and cosine functions be added to make a square-wave function?
yes
Can a bunch of sine and cosine functions be added to make a triangle function?
yes
The second-Fourier-Series component has a frequence that is ____ the fundamental frequency.
exactly two times
The first Fourier Series component is called the fundamental or first harmonic.
true
The Fourier Series components are also called harmonics.
true
The Fourier Series componenents are all
sinusoids
If the time-domain signal x(t) is not periodic, the X(f) will be the Fourier Transform.
true
If the time-domain signal x(t) is periodic, the X(f) will be the Fourier Series.
true
X(f) is the _____ of the time-domain signal x(t).
Fourier Transform or Fourier Series
The diagram that shows (human voice - electronic signal - EM wave - electronic signal - human voice) introduces
signal processing
Which domain is used when making a Bode plot?
jw domain
Bode Plots deal with ______ input and output signals.
sinusoidal
Time invariant in a LTI system means a time delay of the input signal results in ______ time delay of the output signal.
the same
Which of the following is true about a LTI system?
both of these
The signals scale
Two times the input signal results in two times the output signal.
LTI stands for
Linear and Time Invariant
The delay TF has Bode-gain that _____ as frequency increases.
remains constant
The delay has Bode-phase that _____ as frequency increases.
decreases
The second-order lag has Bode-gain slope of ____ after the corner
-40dB/decade
The integrator has Bode-gain slope of ____ over all frequencies.
-20 dB/decade
The differentiator has Bode-gain slope of ____ over all frequencies.
20dB/decade
The first-order lag has a Bode-gain slope of _____ after the corner.
-20dB/decade
The first-order lead has a Bode-gain slope of _____ after the corner.
20dB/decade
G(s) = exp(-a*s)
delay
G(s) = s
differentiator
G(s) = 1/s
integrator
G(s) = a/(s^2 + b*s + w1^2)
second-order lag
(s) = a / ( (s+w1) * (s+w2) )
double lag
G(s) = a/(s+w1)
first-order lag
G(s) = a*(s+w1)
first-order lead
G(s)=(s+a)/(s+b), and in Bode-plot form, G(s)=
(a/b)(1+s/a)/(1+s/b)
G(s)=1/(s^2+a*s+b), and in Bode-plot form, G(s)=
(1/b)/(1+a*s/b+s^2/b)
G(s)=1/((s+b)(s+a)), and in Bode-plot form, G(s)=
(1/(a*b))/((1+s/b)(1+s/a))
G(s)=1/(s(s+a)), and in Bode-plot form, G(s)=
(1/a)/(s(1+s/a))
G(s)=1/((s+b)(s+a)), and in Bode-plot form, G(s)=
(1/(a*b))/((1+s/b)(1+s/a))
The system TF must be written in _____ in order to manually sketch asymptotic Bode plots
factored-polynomial form
The system TF must be written in _____ in order to manually sketch asymptotic Bode plots
system transfer functions
Deviations of asymptotic Bode plots from actual Bode plots occur at the
corners
Asympotic Bode plots are
straight-line approximations
A delta function has _____ height and _____ width and _____ area.
infinite, zero, unit
The width of the rectangular pulse (hat function) is
tau
The height of the rectangular pulse (hat function) is
A
The integral from -infinity to +infinity of delta(t) is
1
Equations 6,7 and 8 were derived from equation 4, which is _____ the capability of the student of beginning calculus.
well within
Equations 6,7 and 8 were derived from equation
4
Equations 6,7 and 8 have something in common:
no imaginary part
Equation 7 is easily visualized as most like
1/f^2
Equation 8 is the Fourier transform of a
delta function
Equation 7 is the Fourier transform of a
two-sided exponential
Equation 6 is a
sinc function
Equation 6 is the Fourier transform of a
pulse or hat function
X_bar_n in equation 3 is ____ and X_bar(f) in equation 4 is a ____.
discrete set, continuous function
X_bar_n in equation 3 and X_bar(f) in equation 4 are both complex
true
The period of the periodic signal in equations 1-3 is
T
An, Bn, and Xn are _____ in number theoretically, and _____ in practice.
infinite, small
Equation 4 is theoretically interesting, but is not practical because of the infinite limits.
false
Equation 4 is theoretically interesting, but is not practical because of the infinite limits.
x(t)
Which equation shows how to calculate the Fourier transform of a periodic or non-periodic signal?
4
Which equation shows how to calculate the Fourier transform of a non-periodic signal?
4
Which equation shows how to calculate the Fourier series complex coefficients for a periodic signal?
3
Which equation shows how to calculate the Fourier series cosine amplitudes for a periodic signal?
1
Which equation shows how to calculate the Fourier series sine amplitudes for a periodic signal?