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
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 2
Resistor performs amplitude scaling when x (t) is voltage, a is resistance and y (t) is output current.
A. True
B. False
Question 3
Which of the following is an example of amplitude scaling?
A. Electronic amplifier
B. Electronic attenuator
C. Both amplifier and attenuator
D. Adder
Question 4
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 5
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 6
Is discrete time convolution possible?
A. True
B. False
Question 7
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 8
A system which is linear is said to obey the rules of
A. scaling
B. additivity
C. both scaling and additivity
D. homogeneity
Question 9
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 10
Which of the component performs integration operation?
A. Resistor
B. Diode
C. Capacitor
D. Inductor
Question 11
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 12
Should real time instruments like oscilloscopes be time invariant?
A. Yes
B. Sometimes
C. Never
D. They have no relation with time variance
Question 13
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 14
Y (t) = x (2t) is ________
A. Compressed signal
B. Expanded signal
C. Shifted signal
D. Amplitude scaled signal by a factor of 2
Question 15
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 16
Does the following discrete system have the parameter of memory, y[n] = x[n-1] + x[n] ?
A. Yes
B. No
Question 17
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 18
All causal systems must have the component of
A. memory
B. time invariance
C. stability
D. linearity
Question 19
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 20
Comment on the causality of y[n] = n*x[n].
A. Time invariant
B. Time varying
C. Non causal
D. Causal
Question 21
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 22
Comment on the causality of y[n] = x[-n].
A. Time invariant
B. Causal
C. Non causal
D. Time varying
Question 23
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 24
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 25
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 26
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 27
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 28
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 29
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 30
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 31
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 32
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 33
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 34
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 35
Comment on the linearity of y[n] = n*x[n].
A. Linear
B. Only additive
C. Not scalable
D. Non linear
Question 36
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 37
Is the system y(t) = Rx(t), where R is a arbitrary constant, a memoryless system?
A. Yes
B. No
Question 38
Which of the passive component performs differentiation operation?
A. Resistor
B. Capacitor
C. Inductor
D. Amplifier