# Sampling - Electronic Engineering (MCQ) questions & answers

1)   The scaling of a sequence x[n] by a factor α is given by

a. y[n] = α [x[n]]2
b. y[n] = α x[n2]
c. y[n] = α x[n]
d. y[n] = x[n]x[-n]
 Answer  Explanation ANSWER: y[n] = α x[n] Explanation: No explanation is available for this question!

2)   Superposition of signals in a linear system refers to the

a. Output that is product of all the signals
b. Output that is sum of all the signals
c. Output that is of highest amplitude of all the signals
d. Output that is of largest spectrum of all the signals
 Answer  Explanation ANSWER: Output that is sum of all the signals Explanation: No explanation is available for this question!

3)   Causal systems are the systems in which

a. The output of the system depends on the present and the past inputs
b. The output of the system depends only on the present inputs
c. The output of the system depends only on the past inputs
d. The output of the system depends on the present input as well as the previous outputs
 Answer  Explanation ANSWER: The output of the system depends on the present and the past inputs Explanation: No explanation is available for this question!

4)   Time reversal of a discrete time signal refers to

a. y[n] = x[-n+k]
b. y[n] = x[-n]
c. y[n] = x[-n-k]
d. y[n] = x[n-k]
 Answer  Explanation ANSWER: y[n] = x[-n] Explanation: No explanation is available for this question!

5)   Time shifting of discrete time signal means

a. y[n] = x[n-k]
b. y[n] = x[-n-k]
c. y[n] = -x[n-k]
d. y[n] = x[n+k]
 Answer  Explanation ANSWER: y[n] = x[n-k] Explanation: No explanation is available for this question!

6)   A signal x[n] is anti symmetric or odd when

a. x[-n] = x[n] • x[n]
b. x[n] = -x[n]
c. x[n] = [x[n]]2
d. x[-n] = -x[n]
 Answer  Explanation ANSWER: x[-n] = -x[n] Explanation: No explanation is available for this question!

7)   The discrete impulse function is defined by

a. δ(n) = 1, n ≥ 0
= 0, n ≠ 1
b. δ(n) = 1, n = 0
= 0, n ≠ 1
c. δ(n) = 1, n ≤ 0
= 0, n ≠ 1
d. δ(n) = 1, n ≤ 0
= 0, n ≥ 1
 Answer  Explanation ANSWER: δ(n) = 1, n = 0 = 0, n ≠ 1 Explanation: No explanation is available for this question!

8)   A discrete time signal may be

1) Samples of a continuous signal
2) A time series which is a domain of integers
3) Time series of sequence of quantities
4) Amplitude modulated wave

a. 1, 2 and 3 are correct
b. 1 and 2 are correct
c. 1 and 3 are correct
d. All the four are correct
 Answer  Explanation ANSWER: 1, 2 and 3 are correct Explanation: No explanation is available for this question!

9)   Roll-off factor is

a. The bandwidth occupied beyond the Nyquist Bandwidth of the filter
b. The performance of the filter or device
c. Aliasing effect
d. None of the above
 Answer  Explanation ANSWER: The bandwidth occupied beyond the Nyquist Bandwidth of the filter Explanation: No explanation is available for this question!

10)   The Nyquist theorem for sampling

1) Relates the conditions in time domain and frequency domain
2) Helps in quantization
3) Limits the bandwidth requirement
4) Gives the spectrum of the signal

a. 1, 2 and 3 are correct
b. 1 and 2 are correct
c. 1 and 3 are correct
d. All the four are correct
 Answer  Explanation ANSWER: 1 and 3 are correct Explanation: No explanation is available for this question!