Signals & Systems MCQs : This section focuses on the "Signals & Systems". These Multiple Choice Questions (MCQs) should be practiced to improve the Signals & Systems skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
Amplifiers, motors, filters etc. are examples for which type of system?
A. Distributed parameter systems
B. Unstable systems
C. Discrete time systems
D. Continuous time systems
Question 2
A system produces zero output for one input and same gives the same output for several other inputs. What is the system called?
A. Non – invertible System
B. Invertible system
C. Non – causal system
D. Causal system
Question 3
What are the tools used in a graphical method of finding convolution of discrete time signals?
A. Plotting, shifting, folding, multiplication, and addition in order
B. Scaling, shifting, multiplication, and addition in order
C. Scaling, multiplication and addition in order
D. Scaling, plotting, shifting, multiplication and addition in order
Question 4
An example of a discrete set of information/system is
A. the trajectory of the Sun
B. data on a CD
C. universe time scale
D. movement of water through a pipe
Question 5
Resistor performs amplitude scaling when x (t) is voltage, a is resistance and y (t) is output current.
A. True
B. False
Question 6
Comment on the causality of y[n] = x[-n].
A. Time invariant
B. Causal
C. Non causal
D. Time varying
Question 7
When we take up design of systems, ideally how do we define the stability of a system?
A. A system is stable, if a bounded input gives a bounded output, for some values of the input
B. A system is unstable, if a bounded input gives a bounded output, for all values of the input
C. A system is stable, if a bounded input gives a bounded output, for all values of the input
D. A system is unstable, if a bounded input gives a bounded output, for some values of the input
Question 8
A system is said to be defined as non causal, when
A. the output at the present depends on the input at an earlier time
B. the output at the present does not depend on the factor of time at all
C. the output at the present depends on the input at the current time
D. the output at the present depends on the input at a time instant in the future
Question 9
Is the system y(t) = Rx(t), where R is a arbitrary constant, a memoryless system?
A. Yes
B. No
Question 10
All causal systems must have the component of
A. memory
B. time invariance
C. stability
D. linearity
Question 11
Which of the component performs integration operation?
A. Resistor
B. Diode
C. Capacitor
D. Inductor
Question 12
What is the convolution of a signal with an impulse?
A. Signal itself
B. Impulse
C. A new signal
D. Signal multiplied by impulse
Question 13
AM radio signal is an example for __________
A. y (t) = a x (t)
B. y (t) = x1 (t) + x2 (t)
C. y (t) = x1 (t) * x2 (t)
D. y (t) = -x(t)
Question 14
Does the following discrete system have the parameter of memory, y[n] = x[n-1] + x[n] ?
A. Yes
B. No
Question 15
Which of the following is an example of physical device which adds the signals?
A. Radio
B. Audio mixer
C. Frequency divider
D. Subtractor
Question 16
Comment on the linearity of y[n] = n*x[n].
A. Linear
B. Only additive
C. Not scalable
D. Non linear
Question 17
Should real time instruments like oscilloscopes be time invariant?
A. Yes
B. Sometimes
C. Never
D. They have no relation with time variance
Question 18
Construct the inverse system of y(t) = 2x(t)
A. y(t) = 0.5x(t)
B. y(t) = 2x(t)
C. y(2t) = x(t)
D. y(t) = x(2t)
Question 19
A time invariant system is a system whose output
A. increases with a delay in input
B. decreases with a delay in input
C. remains same with a delay in input
D. vanishes with a delay in input
Question 20
Time scaling is an operation performed on _______
A. Dependent variable
B. Independent variable
C. Both dependent and independent variable
D. Neither dependent nor independent variable
Question 21
y(t) = x(t-2) + x(2-t). Comment on its causality:
A. Causal
B. Time variant
C. Non causal
D. All of the above
Question 22
Y (t) = x (2t) is ________
A. Compressed signal
B. Expanded signal
C. Shifted signal
D. Amplitude scaled signal by a factor of 2
Question 23
y(t) = sin(x(t-1)) : Comment on its memory aspects.
A. Having memory
B. Needn’t have memory
C. Memoryless system
D. Time invariant system
Question 24
Comment on the causality of y[n] = n*x[n].
A. Time invariant
B. Time varying
C. Non causal
D. Causal
Question 25
Which of the passive component performs differentiation operation?
A. Resistor
B. Capacitor
C. Inductor
D. Amplifier
Question 26
In discrete signal, if y [n] = x [k*n] and k>1 then ______
A. Some samples are lost from x [n]
B. Some samples are added to x [n]
C. It has no effect on samples
D. Samples will be increased with factor k
Question 27
All real time systems concerned with the concept of causality are
A. non causal
B. causal
C. neither causal nor non causal
D. memoryless
Question 28
Y (t) = x (t/5) is _______
A. Compressed signal
B. Expanded signal
C. Time shifted signal
D. Amplitude scaled signal by factor 1/5
Question 29
What is the commutative property?
A. x(n)*h(n)=h(n)*x(n)
B. x(n)+h(n)=h(n)+x(n)
C. x(n)**h(n)=h(n)**x(n)
D. x(n)h(n)=h(n)x(n)
Question 30
Which of the following is an example of amplitude scaling?
A. Electronic amplifier
B. Electronic attenuator
C. Both amplifier and attenuator
D. Adder
Question 31
Which among the following systems are described by partial differential functions?
A. Causal Systems and Dynamic systems
B. Distributed parameter systems and linear systems
C. Distributed parameter systems and Dynamic systems
D. Causal systems and linear systems
Question 32
Is discrete time convolution possible?
A. True
B. False
Question 33
The type of systems which are characterized by input and the output quantized at certain levels are called as
A. analog
B. discrete
C. continuous
D. digital
Question 34
How is discrete time convolution represented?
A. x[n] + h[n]
B. x[n] – h[n]
C. x[n] * h[n]
D. x[n] + h[n]
Question 35
Choose the properties which are followed by a discrete time convolution?
A. Associative, commutative, distributive
B. Associative
C. Commutative and distributive
D. Distributive and associative
Question 36
y[t]= ∫x[t],t ranges from 0 to t. Is the system a memoryless one?
A. Yes
B. No
C. Both memoryless and having memory
D. None of the Mentioned
Question 37
What is the associative property of discrete time convolution?
A. [x1(n) * x2(n)]*h(n) = x1(n)* [x2(n)*h(n)]
B. [x1(n) * x2(n)]+h(n) = x1(n) + [x2(n)*h(n)]
C. [x1(n) + x2(n)]*h(n) = x1(n)* [x2(n)+h(n)]
D. [x1(n) * x2(n)]h(n) = x1(n) [x2(n)*h(n)]
Question 38
A system which is linear is said to obey the rules of
A. scaling
B. additivity
C. both scaling and additivity
D. homogeneity