Signal Processing MCQ Questions & Answers

81

The input x(t) and the output y(t) of a continuous- time system are related as
$$y\left( t \right) = \int\limits_{t - T}^t {x\left( u \right)du} $$
The system is

A) Linear and time-variant B) Linear and time-invariant C) Non-linear and time-variant D) Non-linear and time-invariant

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

82

The N-point DFT of a sequence x[n], 0 ≤ n ≤ N - 1 is given by
$$X\left[ K \right] = \frac{1}{{\sqrt N }}\sum\limits_{n = 0}^{N - 1} {x\left[ n \right]} {e^{ - j\frac{{2\pi }}{N}nK}},0 \leqslant K \leqslant N - 1$$
Denote this relation as X = DFT(x). For N = 4, which one of the following sequences satisfies DFT (DFT (x)) = x.

A) x = [1 2 3 r] B) x = [1 2 3 2] C) x = [1 3 2 2] D) x = [1 2 2 3]

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

83

Convolution of x(t + 5) with impulse function δ(t - 7) is equal to

A) x(t - 12) B) x(t + 12) C) x(t - 2) D) x(t + 2)

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

84

The Laplace transform of e^αt cos (αt) is equal to

A) $${{\left( {s - \alpha } \right)} \over {{{\left( {s - \alpha } \right)}^2} + {\alpha ^2}}}$$ B) $${{\left( {s + \alpha } \right)} \over {{{\left( {s + \alpha } \right)}^2} + {\alpha ^2}}}$$ C) $${1 \over {{{\left( {s - \alpha } \right)}^2}}}$$ D) None of these

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

85

A system is described by the following differential equation, where u(t) is the input to the system and y(t) is the output of the system. y(t) + 5y(t) = u(t)
When y(0) = 1 and u(t) is a unit step function, y(t) is

A) 0.2 + 0.8e^-5t B) 0.2 - 0.2e^-5t C) 0.8 + 0.2e^-5t D) 0.8 - 0.8e^-5t

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

86

Consider the following statements for continuous-time linear time invariant (LTI) systems.
1. There is no bounded input bounded output (BIBO) stable system with a pole in the right half of the complex plane.
2. There is no causal and BIBO stable system with a pole in the right half of the complex plane.
Which one among the following is correct?

A) Both 1 and 2 are true B) Both 1 and 2 are not true C) Only 1 is true D) Only 2 is true

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

87

The Fourier transform F{e^-t u(t)} is equal to $${1 \over {1 + j2\pi f}}.$$ Therefore, $$F\left\{ {{1 \over {1 + j2\pi f}}} \right\}$$ is

A) e^f u(f) B) e^-f u(f) C) e^f u(-f) D) e^-f u(-f)

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

88

A system with transfer function H(z) has impulse response h(n) defined as h(2) = 1, h(3) = -1 and h(k) = 0 otherwise. Consider the following statements.
S₁ : H(z) is a low-pass filter.
S₂ : H(z) is an FIR filter.
Which of the following is correct?

A) Only S₂ is true B) Both S₁ and S₂ are false C) Both S₁ and S₂ are true, and S₂ is a reason for S₁ D) Both S₁ and S₂ are true, but S₂ is not a reason for S₁

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

89

The Laplace transform of the causal periodic square wave of period T shown in the figure below is It
Signal Processing mcq question image

A) $$F\left( s \right) = \frac{1}{{1 + {e^{ - \frac{{sT}}{2}}}}}$$ B) $$F\left( s \right) = \frac{1}{{s\left( {1 + {e^{ - \frac{{sT}}{2}}}} \right)}}$$ C) $$F\left( s \right) = \frac{1}{{s\left( {1 - {e^{ - \frac{{sT}}{2}}}} \right)}}$$ D) $$F\left( s \right) = \frac{1}{{1 - {e^{ - sT}}}}$$

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

90

A rectangular pulse of duration T is applied to a filter matched to this input. The output of the filter is a

A) Rectangular pulse of duration T B) Rectangular pulse of duration 2T C) Triangular pulse D) Sine function

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

Signal Processing MCQ Questions & Answers | ECE