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WorksheetsEC 8352 SS - IAT#2
Total questions: 50
Worksheet time: 50mins
When
ω =0 in the signal x(t)=A est , where s=α+jω , the signal x(t) representsExponential Signal
Step SIgnal
Ramp Signal
Sinusoidal Signal
The mathematical operation
∫−∞∞ x(t) e−st dt is calledLaplace TRansform
Two sided Laplace Transfrom
One sided Laplace Transform
Generalized frequency domain transform
The term
ω in s=σ+jω is calledFrequency
Real Frequency
Complex Frequency
Critical Frequency
The Laplace transform will to ll transform a time domain signal
s - domain
Z- domain
For a stable causal system ------------------should lie on left half of the s-plane
Poles
Zeros
The Laplace transform is used to transform a frequency domain signal to complex frequency domain
True
False
The inverse Laplace transform of the transfer function gives the impulse response
True
False
The direct form - I structure uses less number of integrator than direct form II structure
True
False
The ROC of a causal signal x(t) is
entire s - plane
region in between two abscissa of convergence
right of abscissa of convergence
left of abscissa of convergence
The Laplace transform of the causal signal
tn u(t) issn−1n!
snn!
sn
none of the above
If x(t) and X(s) are Laplace transform pairs, then Laplace transform of
e−at x(t) isX(s−a)
X(s+a)
eas X(s)
e−as X(s)
If x(t) and X(s) are Laplace transform pairs, then Laplace transform of
tx(t) is∫0∞X(s) ds
∫s∞X(s) ds
s1∫0∞X(s) ds
s1∫s∞X(s) ds
If x(t) and X(s) are Laplace transform pair, and X(s) is rational, then which of the following statements are true.
(i) poles and zeros are critical frequencies
(ii) the ROC of X(s) does not include poles
(iii) the number of finite zeros will be less than or equal to number of poles
i and ii only
i only
ii only
all the above
If x(t) and X(s) are Laplace transform pair, and X(s) is rational, the which of the following statements are true regarding the ROC of X(s)
(i) The ROC is bounded by poles or extends to infinity
(ii) If x(t) is right sided, then ROC is right most pole.
(iii) If x(t) is left sided, then ROC is left of left most people.
i only
ii only
ii and iii only
all the above
The inverse Laplace transform
X(s)=s2+2s+52 isx(t)=e−tcos2t
x(t)=e−tsin2t
x(t)=e−2tcos5t
x(t)=e−2tsin5t
The inverse Laplace transform of
X(s)=s+54 for ROC Re{s}>−4 and Re{s}<−4 are respectively4e−5tu(t) and 4e−5tu(−t)
4e5tu(t) and 4e5tu(−t)
4e−5tu(t) and −4e−5tu(−t)
−4e−5tu(t) and −4e−5tu(−t)
For a continuous time LTI system which of the following statements are true
(i) The transfer function is ration of Laplace transform of output and input
(ii) The transfer function is ratio of Laplace transform of input and output
(iii) The transfer function is Laplace transform of impulse response
i only
i and iii only
ii only
iii only
If x(t), y(t) are input, output and impulse response of LTI continuous time system respectively then,
h(t) = x(t) ⋅ y(t)
x(t) = y(t) ⋅ h(t)
y(t) = x(t) ⋅ h(t)
y(t) = h(t) ⋅ h(t)
The convolution of u(t) with u(t) will be equal to,
δ(t)
u(t)
t u(t)
t2u(t)
The convolution of e−at u(t) with e−at u(t) will be a equal
t u(t)
e−at u(t)
e−2at u(t)
t e−at u(t)
Fourier series is useful for frequency domain analysis of ---------- signals
Periodic
Aperiodic
Linear
Nonlinear
The ratio of Fourier transform of output and input of a system is called------------------
Transfer Function
Impulse response
output response
input response
The Fourier transform of impulse response will be equal to -------------------------
Transfer function
output
input
none of the above
The magnitude line spectrum is symmetric and phase line spectrum is anti symmetric
True
False
For waveform with even spectrum , the Fourier coefficient is always zero
True
False
For waveforms with odd symmetry, the Fourier Coefficients are always zero
True
False
An alternating waveform will always have even harmonic only
True
False
An even signal with halfwave symmetry will always have been harmonics of cosine terms
True
False
An odd signal with halfwave symmetry will always have been harmonics of sine terms
True
False
The shifting of vertical axis of a waveform , will not affect the even/ odd symmetry
True
False
In frequency spectrum using Fourier transform, the magnitude spectrum will have even symmetry and phase spectrum will have odd symmetry
True
False
The fourier transform of a periodic signal will be summation of impulse
True
False
The total average power in a periodic signal is equal to the sum of power in all of its harmonic
True
False
Fourier transform is useful for frequency domain analysis of both periodic and non periodic signal
True
False
Laplace transform is a generalized transform and Fourier transform is particular transform
True
False
The value of
e−∞ is------------------
(a)
The value of
e∞ is------------------
(a)
The value of cos 0 is------------------
(a)
The value of sin 0 is------------------
(a)
Which of the following is the Analysis Equation of Fourier Transform?
F(w)=∫−∞∞f(t)ejwt dt
F(w)=∫0∞f(t)ejwtdt
F(w)=∫0∞f(t)e−jwtdt
F(w)=∫−∞∞f(t)e−jwtdt
Find the Fourier Transform of an Exponential signal
f(t)=e−atu(t),a>0a+jw1
a−jw1
−a+jw1
−a−jw1
The Fourier Transform of a function
X(t) is X(w). what will be the fourier transform of dtdX(t) ?jfX(f)
j2πfX(f)
dtdX(f)
jfX(f)
Find the Inverse Fourier transform of δ(w)
2π1
2π
π1
π
Find the inverse Fourier Transform of f(t)=1
u(t)
δ(t)
e−t
jw1
f(x)=1, 0<x<∞ cannot be represented by a Fourier Integral
True
False
Find the convolution of the signals X1(t)=e−2tu(t) and X2(t)=e−3tu(t)
e−2tu(t)−e−3tu(t)
e−2tu(t)+e−3tu(t)
e2tu(t)−e3tu(t)
e2tu(t)−e−3tu(t)
Which one is the correct definition of Laplace Transform?
F(s)=∫0∞e−stf(t)dt
F(s)=∫0tf(t)g(t−u)
What is the Laplace Transform for f(t)=t3 ?
s31
s32
s46
s33
What is Laplace Transform for e−2t ?
s−21
s+21
s2
s21
What is Laplace Transform for sin 2t ?
s2+22
s2+2s
s2+42
s2+4s
