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Consider the following statements for continuous-time linear time invariant (LTI) systems.<br>1. There is no bounded input bounded output (BIBO) stable system with a pole in the right half of the complex plane.<br>2. There is no causal and BIBO stable system with a pole in the right half of the complex plane.<br>Which one among the following is correct?
A
Both 1 and 2 are true
B
Both 1 and 2 are not true
C
Only 1 is true
D
Only 2 is true
Correct Answer:
Only 2 is true
Consider a system whose input r and output y are related by the equation $$y\left( t \right) = \int\limits_{ - \infty }^\infty {x\left( {t - \tau } \right)} h\left( {2\tau } \right)d\tau $$
Where h(t) is shown in the graph
Which of the following four properties are possessed by the system? BIBO: Bounded input gives a bounded output
Causal: The system is causal.
LP : The system is low pass.
LTI: The system is linear and time-invariant.
A
Causal, LP
B
BIBO, LTI
C
BIBO, Causal, LTI
D
LP, LTI
The transfer function of a discrete time LTI system is given by
$$H\left( z \right) = {{2 - {3 \over 4}{z^{ - 1}}} \over {1 - {3 \over 4}{z^{ - 1}} + {1 \over 8}{z^{ - 2}}}}$$
Consider the following statements:
S
1
: The system is stable and causal for
$$ROC:\left| z \right| > {1 \over 2}$$
S
2
: The system is stable but not causal for
$$ROC:\left| z \right| S
3
: The system is neither stable nor causal for
$$ROC:{1 \over 4} Which one of the following statements is valid?
A
Both S<sub>1</sub> and S<sub>2</sub> are true
B
Both S<sub>2</sub> and S<sub>3</sub> true
C
Both S<sub>1</sub> and S<sub>3</sub> are true
D
S<sub>1</sub>, S<sub>2</sub> and S<sub>3</sub> are all true
Letx(t) be the input and y(t) be the output of a continuous time system. Match the system properties P
1
, P
2
and P
3
with system relations R
1
, R
2
, P
3
, P
4
.
Properties
P
1
: Linear but NOT time-invariant
P
2
: Time-invariant but NOT linear
P
3
: Linear and time-invariant
Relations
R
1
: y(t) = t
2
x(t)
R
2
: y(t) = t |x(t)|
R
3
: y(t) = |x(t)|
R
4
: y(t) = x(t - 5)
A
(P<sub>1</sub>, R<sub>1</sub>), (P<sub>2</sub>, R<sub>3</sub>), (P<sub>3</sub>, R<sub>4</sub>)
B
(P<sub>1</sub>, R<sub>2</sub>), (P<sub>2</sub>, P<sub>3</sub>), (P<sub>3</sub>, R<sub>4</sub>)
C
(P<sub>1</sub>, R<sub>3</sub>), (P<sub>2</sub>, R<sub>1</sub>), (P<sub>3</sub>, R<sub>2</sub>)
D
(P<sub>1</sub>, R<sub>1</sub>), (P<sub>2</sub>, R<sub>2</sub>), (P<sub>3</sub>, R<sub>3</sub>)
A stable linear time invariant (LTI) system has a transfer function $$H\left( s \right) = {1 \over {{s^2} + s - 6}}.$$ To make this system causal it needs to be cascaded with another LTI system having a transfer function H
1
(s). A correct choice for H
1
(s) among the following options is
A
s + 3
B
s - 2
C
s - 6
D
s + 1
The impulse response functions of four linear systems S
1
, S
2
, S
3
, S
4
are given respectively by
$${h_1}\left( t \right) = 1,$$ $${h_2}\left( t \right) = u\left( t \right),$$ $${h_3}\left( t \right) = \frac{{u\left( t \right)}}{{t + 1}},$$ $${h_4}\left( t \right) = {e^{ - 3t}}u\left( t \right)$$
Where u(t) is the unit step function. Which of these systems is time invariant, causal, and stable?
A
S<sub>1</sub>
B
S<sub>2</sub>
C
S<sub>3</sub>
D
S<sub>4</sub>
Let h(t) denote the impulse response of a causal system with transfer function $${1 \over {s + 1}}.$$ Consider the following three statements:
S
1
: The system is stable.
S
2
: $${{h\left( {t + 1} \right)} \over {h\left( t \right)}}$$ independent of t for t > 0.
S
3
: A non-causal system with the same transfer function is stable.
For the above system,
A
Only S<sub>1</sub> and S<sub>2</sub> are true
B
Only S<sub>2</sub> and S<sub>3</sub> are true
C
Only S<sub>1</sub> and S<sub>3</sub> are true
D
S<sub>1</sub>, S<sub>2</sub> and S<sub>3</sub> are true
A linear time invariant system is said to be BIBO stable if and only if the ROC of the system function _____________
A
Includes unit circle
B
Excludes unit circle
C
Is an unit circle
D
None of the mentioned
Input x(t) and output y(t) of an LTI system are related by the differential equation y"(t) - y'(t) - 6y(t) = x(t). If the system is neither causal nor stable, the impulse response h(t) of the system is
A
$${1 \over 5}{e^{3t}}u\left( { - t} \right) + {1 \over 5}{e^{ - 2t}}u\left( { - t} \right)$$
B
$$ - {1 \over 5}{e^{3t}}u\left( { - t} \right) + {1 \over 5}{e^{ - 2t}}u\left( { - t} \right)$$
C
$${1 \over 5}{e^{3t}}u\left( { - t} \right) - {1 \over 5}{e^{ - 2t}}u\left( t \right)$$
D
$$ - {1 \over 5}{e^{3t}}u\left( { - t} \right) - {1 \over 5}{e^{ - 2t}}u\left( t \right)$$
Consider the following statements regarding a linear discrete-time system: H (z) = z2+1/(z+0.5)(z-0.5) 1. The system is stable 2. The initial value of h(0) of the impulse response is -4 3. The steady-state output is zero for a sinusoidal discrete time input of frequency equal to one-fourth the sampling frequency Which of these statements are correct?
A
1,2 and 3
B
1 and 2
C
1 and 3
D
2 and 3
The impulse response and the excitation function of a linear time invariant causal system are shown in figure (a) and (b) respectively. The output of the system at t = 2 sec is equal to
A
0
B
$$\frac{1}{2}$$
C
$$\frac{3}{2}$$
D
1