Introduction to Signals and Systems - Electronic Engineering (MCQ) questions & answers

1)   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  Explanation 

ANSWER: a shift in the input signal also results in the corresponding shift in the output

Explanation:
No explanation is available for this question!


2)   Which among the below specified conditions/cases of discrete time in terms of real constant 'a', represents the double-sided decaying exponential signal?

a. a > 1
b. 0 < a < 1
c. a < -1
d. -1 < a < 0
Answer  Explanation 

ANSWER: -1 < a < 0

Explanation:
No explanation is available for this question!


3)   An equalizer used to compensate the distortion in the communication system by faithful recovery of an original signal is nothing but an illustration of _________

a. Static system
b. Dynamic system
c. Invertible system
d. None of the above
Answer  Explanation 

ANSWER: Invertible system

Explanation:
No explanation is available for this question!


4)   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
Answer  Explanation 

ANSWER: 1, 2, 3 & 4

Explanation:
No explanation is available for this question!


5)   Under which conditions does an initially relaxed system become unstable?

a. only if bounded input generates unbounded output
b. only if bounded input generates bounded output
c. only if unbounded input generates unbounded output
d. only if unbounded input generates bounded output
Answer  Explanation 

ANSWER: only if bounded input generates unbounded output

Explanation:
No explanation is available for this question!


6)   Which condition determines the causality of the LTI system in terms of its impulse response?

a. Only if the value of an impulse response is zero for all negative values of time
b. Only if the value of an impulse response is unity for all negative values of time
c. Only if the value of an impulse response is infinity for all negative values of time
d. Only if the value of an impulse response is negative for all negative values of time
Answer  Explanation 

ANSWER: Only if the value of an impulse response is zero for all negative values of time

Explanation:
No explanation is available for this question!


7)   An amplitude of sinc function that passes through zero at multiple values of an independent variable 'x' ______

a. Decreases with an increase in the magnitude of an independent variable (x)
b. Increases with an increase in the magnitude of an independent variable (x)
c. Always remains constant irrespective of variation in magnitude of 'x'
d. Cannot be defined
Answer  Explanation 

ANSWER: Decreases with an increase in the magnitude of an independent variable (x)

Explanation:
No explanation is available for this question!


8)   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  Explanation 

ANSWER: sinusoid signals multiplied by decaying exponentials

Explanation:
No explanation is available for this question!


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
Answer  Explanation 

ANSWER: Sampling

Explanation:
No explanation is available for this question!


10)   Which mathematical notation specifies the condition of periodicity for a continuous time signal?

a. x(t) = x(t +T0)
b. x(n) = x(n+ N)
c. x(t) = e-αt
d. None of the above
Answer  Explanation 

ANSWER: x(t) = x(t +T0)

Explanation:
No explanation is available for this question!