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Free download in PDF Signals and Systems Multiple Choice Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams. These short solved questions or quizzes are provided by Gkseries.
(1)
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
(2)
The type of systems which are characterized by input and the output capable of taking any value in a particular set of values are called as
[A]
Analog
[B]
Discrete
[C]
Digital
[D]
Continuous
(3)
Should real time instruments like oscilloscopes be time invariant?
[A]
Yes
[B]
Sometimes
[C]
Never
[D]
They have no relation with time variance
(4)
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
Answer: the output at the present depends on the input at a time instant in the future
(5)
What is the other name of a Continuous Time Unit Impulse Function?
[A]
Dirac delta function
[B]
Unit function
[C]
Area function
[D]
Direct delta function
Answer: Dirac delta function
(6)
Why is the impulse duration important?
[A]
It is zero
[B]
It changes with time
[C]
It approaches zero
[D]
It depends on the situation
Answer: It approaches zero
(7)
What is a doublet function?
[A]
Branch of an impulse function
[B]
The output of an impulse function
[C]
The first derivative of an impulse function
[D]
Any continuous time impulse function has another name that is doublet function
Answer: The first derivative of an impulse function
(8)
How are discrete unit impulse functions and discrete time unit step functions related?
[A]
They are inverse of each other
[B]
∂(n)=u(n)-u(n-1)
[C]
∂(n)=u(n)*2∂
[D]
Integration of unit step function gives unit step function
(9)
Which property of delta function indicates the equality between the area under the product of function with shifted impulse and the value of function located at unit impulse instant ?
[A]
Replication
[B]
Sampling
[C]
Scaling
[D]
Product
(10)
Damped sinusoids are _____
[A]
sinusoid signals multiplied by growing exponentials
[B]
sinusoid signals divided by growing exponentials
[C]
sinusoid signals multiplied by decaying exponentials
[D]
sinusoid signals divided by decaying exponentials
Answer: sinusoid signals multiplied by decaying exponentials
(11)
A system is said to be shift invariant only if______
[A]
a shift in the input signal also results in the corresponding shift in the output
[B]
a shift in the input signal does not exhibit the corresponding shift in the output
[C]
a shifting level does not vary in an input as well as output
[D]
a shifting at input does not affect the output
Answer: a shift in the input signal also results in the corresponding shift in the output
(12)
Which among the following are the stable discrete time systems?
1. y(n) = x(4n)
2. y(n) = x(-n)
3. y(n) = ax (n) + 8
4. y(n) = cos x(n)
[A]
1 & 3
[B]
2 & 4
[C]
1, 3 & 4
[D]
1,2,3 & 4
(13)
If a function f(t) u(t) is shifted to right side by t0,then the function can be expressed as
[A]
f(t – t0) u(t)
[B]
f(t) u(t – t0)
[C]
f(t – t0) u(t – t0)
[D]
f(t +t0) u(t + t0)
Answer: f(t – t0) u(t – t0)
(14)
Which block of the discrete time systems requires memory in order to store the previous input?
[A]
Signal Multiplier
[B]
Unit Delay
[C]
Adder
[D]
None of the above
(15)
The covariance function of a band limited white noise is
[A]
A Dirac delta function
[B]
An exponentially decreasing function
[C]
A sinc function
[D]
A sinc2 function
(16)
A discrete LTI system is non-causal if its impulse response is
[A]
anu(n -2)
[B]
an-2u(n)
[C]
an+2u(n)
[D]
anu(n +2)
(17)
What does the signalling rate in the digital communication system imply?
[A]
Number of digital pulses transmitted per second
[B]
Number of digital pulses transmitted per minute
[C]
Number of digital pulses received per second
[D]
Number of digital pulses received per minute
Answer: Number of digital pulses transmitted per second
(18)
What does the transfer function of a system describe for the system ?
[A]
Only zero-input response
[B]
Only zero-state response
[C]
Both zero-input and zero-state response
[D]
Neither zero-input response nor zero-state response
Answer: Only zero-state response
(19)
Which one of the following is the correct statement ?
The system characterized by the equation y(t) = ax(t) + b is
[A]
linear for any value of b
[B]
linear if b > 0
[C]
linear if b < 0
[D]
non-linear
(20)
Which one of the following systems described by the following input-output relations is non-linear ?
[A]
y(n) = n x(2n)
[B]
y(n) = x (n2)
[C]
y(n) = n2x(n)
[D]
y(n) = x2(n)
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