Q.1

unit step is a

  • energy signal
  • power signal
  • neither energy nor power signal
  • none
Q.2

Fourier series is applicable for

  • periodic
  • finite duration
  • non periodic
  • a and b
Q.3

The state equations are in the form

  • X = AX + BW
  • X = AX + Bu
  • X = AX + Bx
  • either (a) or (b)
Q.4

Assertion (A): In complex frequency s = σ + jω, the terms s and ω are nepar frequency and radin frequency.

Reason (R): If ω =the graph of Kest will be a decaying exponential if s <

  • Both A and R are correct and R is correct explanation of A
  • Both A and R are correct but R is not correct explanation of A
  • A is true, R is false
  • A is false, R is true
Q.5

consider the following as regards cumulative disribution function F(x)

  1. 0 ≤ F(x) ≤ 1
  2. F(- ∞) = 0
  3. F(∞) = 1
  4. F(x1) ≤ F(x2) If x1 < x2
Out of above which are correct?
  • 1 and 2 only
  • 1, 2 and 3 only
  • 1, 2, 3 and 4
  • 2 and 4
Q.6

The inverse response of a system h(n) = an∪(n) what is the condition for the system to be BIBO stable?

  • a is real and +ve
  • a is real and -ve
  • |a| > 1
  • |a| < 1
Q.7

An excitation is applied to a system at t = T and the response in zero for -∞ < t < T. This system is

  • non casual
  • stable
  • casual
  • unstable
Q.8

(SI - A)-1 = adj(sI - A)/det (sI - A)

  • True
  • False
Q.9

The eign values of n x n matrix A are the root of the characteristic equation 1λI - AI = 0

  • True
  • False
Q.10

A linear discrete time system has the char. equation z3 - 0.81z =the system is

  • stable
  • marginally stable
  • unstable
  • stability cannot be assessed from the given information
Q.11

Assertion (A): Fourier series can also be written in exponential form.

Reason (R): sin (n ωt) and cos (n ωt) can be expressed as sum or difference of exponentials.

  • Both A and R are correct and R is correct explanation of A
  • Both A and R are correct but R is not correct explanation of A
  • A is true, R is false
  • A is false, R is true
Q.12

Out of the three transforms viz. Z-transform, Laplace transform and Fourier transform

  • all three are used in continuous time domain
  • all three are used in both continuous time domain and discrete time domain
  • Z transform is used in continuous time domain while Laplace and Fourier transforms are used in discrete time domain
  • Z transform is used is discrete time domain while Laplace and Fourier transforms are used in continuous time domain
Q.13

A system has poles at 0.Hz, 1 Hz andHz, zeros at 5 Hz,Hz andHz. The approximate phase of the system response atHz is

  • -90°
  • 90°
  • -180°
Q.14

Fourier transform F(jω) of an arbitrary signal has the property

  • F(jω) = F(- jω)
  • F(jω) = - F(- jω)
  • F(jω) = F*(- jω)
  • F(jω) = - F*(jω)
Q.15

A signal is x + f(t) where x is constant and f(t) is a power signal with zero mean value. The power of the signal is

  • x2
  • x2 + f2(t)
  • more than x2 + f2(t)
  • less than x2 + f2(t)
Q.16

Energy density function is always

  • even
  • odd
  • neither even nor odd
  • both (a) and (b)
Q.17

A number of impulses spaced fron one another form an impulse train.

  • True
  • False
Q.18

In a complex wave, the negative half of the wave is a reproduction of the positive half wave. Then

  • the wave contains only fundamental and third harmonic
  • the wave does not contain even harmonics
  • the wave does not contain odd harmonics
  • the wave does not contain triple harmonics
Q.19

If the number of ways an event may result ins analysed into m successes and n failures, each equally likely to occur, the probability of success in a single trial is m( m + n)

  • True
  • False
Q.20

The signumm function written as [sgn(t)] is defined as

  • sgn(t) = - 1 for t < 0, = 0 for t = 0 and = 1 for t > 0
  • sgn(t) = 1 for t < 0, = 0 for t = 0 and = - 1 for t > 0
  • sgn(t) = 0 for t < 0, = 1 for t = 0 and = 0 for t > 0
  • sgn(t) = 0 for t < 0, = 1 for t3 0
Q.21

The units of F(jω) are volt-seconds.

  • True
  • False
Q.22

A pulse function can be represented as difference of two equal step functions.

  • True
  • False
Q.23

The n state variables can be considered as n components of a state vector.

  • True
  • False
Q.24

Following is a reason of distortion in communication system

  • external interference
  • random variations
  • insufficient Channel Bandwidth
  • all
Q.25

Energy density function is always

  • even
  • odd
  • neither even nor odd
  • both (a) and (b)
Q.26

The integral of k u(t) is

  • a ramp of slope k
    08-92-4.png
  • a ramp of slope 1/k
    08-92-4.png
  • k δ(t)
    08-92-4.png
Q.27

The integral of k u(t) is

  • a ramp of slope k
    08-92-4.png
  • a ramp of slope 1/k
    08-92-4.png
  • k δ(t)
    08-92-4.png
Q.28

The units of F(jω) are volt-seconds.

  • True
  • False
Q.29

Energy density function is always

  • even
  • odd
  • neither even nor odd
  • both (a) and (b)
Q.30

The integral of k u(t) is

  • a ramp of slope k
    08-92-4.png
  • a ramp of slope 1/k
    08-92-4.png
  • k δ(t)
    08-92-4.png
Q.31

Following is a reason of distortion in communication system

  • external interference
  • random variations
  • insufficient Channel Bandwidth
  • all
Q.32

If n is the number of observations and r is the residue, the standard deviation σ =

Q.33

Fourier transform of the unit step function (i.e., u(t) = 1 for t ≥ 0 and u(t) = 0 for t <is

  • pδ (ω)
    11-142-2.png
    11-142-3.png
    11-142-4.png
Q.34

Fourier transform of the unit step function (i.e., u(t) = 1 for t ≥ 0 and u(t) = 0 for t <is

  • pδ (ω)
    11-142-2.png
    11-142-3.png
    11-142-4.png
Q.35

The units of F(jω) are volt-seconds.

  • True
  • False
Q.36

Energy density function is always

  • even
  • odd
  • neither even nor odd
  • both (a) and (b)
Q.37

Following is a reason of distortion in communication system

  • external interference
  • random variations
  • insufficient Channel Bandwidth
  • all
Q.38

The integral of k u(t) is

  • a ramp of slope k
    08-92-4.png
  • a ramp of slope 1/k
    08-92-4.png
  • k δ(t)
    08-92-4.png
Q.39

If n is the number of observations and r is the residue, the standard deviation σ =

Q.40

If and k > 0
X(z) = - In (1 - z-1) with 1 < |z|

  • True
  • False
Q.41

Fourier transform of the unit step function (i.e., u(t) = 1 for t ≥ 0 and u(t) = 0 for t <is

  • pδ (ω)
    11-142-2.png
    11-142-3.png
    11-142-4.png
Q.42

For Ergodic Process

  • ensemble Average equal to time Average
  • ensemble Average is not equal to time Average
  • ensemble Average > Time Average
  • ensemble Average < Time Average
Q.43

Short circuit is the dual of open circuit.

  • True
  • False
Q.44

The impulse response h[n] of a linear time invariant system is given by h[n] = ∪[n + 3 ] + ∪[n --2∪[n -7]. The above system is

  • stable but non-casual
  • stable and casual
  • casual but unstable
  • unstable and not casual
Q.45

A system with input x[n] and output y[n] is given as y[n] = (sin 5/6 pn) x(n) The system is

  • linear, stable and invertible
  • non-linear, stable and non-invertible
  • linear stable, non invertible
  • linear, unstable, invertible
Q.46

Assertion (A): A non-sinusoidal wave can be expressed in terms of sine waves of different frequencies which are multiples of the frequency of fundamental.

Reason (R): If negative half of a complex wave is a reproduction of the positive half, the even harmonics are absent.

  • Both A and R are correct and R is correct explanation of A
  • Both A and R are correct but R is not correct explanation of A
  • A is true, R is false
  • A is false, R is true
Q.47

Highest value of Autocorrelation of a functioncospt is

  • 50
  • 100
  • zero
  • 100/p
Q.48

Which one condition is true to check the periodically for discrete time signal (where K is any integer, N is period, f0 is frequency of signal)

  • f0 = N/K
  • f0 = K/N
  • f0 = K + N
  • f0 = KN
Q.49

The output y(t) of a linear time invariant system is related to its input x(t) by the following equation y(t) = 0.5x(t - td ++ x(t - td) + 0.5 x(t - td + 7). The filter transfer function H(ω) of such a system is given by

  • (1 + cos ωt)e-jωt d
  • (1 + 0.5 cos ωt)e-jωt d
  • (1 + cos ωt)ejωt d
  • (1 - 0.5 cos ωt)e-jωt d
Q.50

Algebraic expression for z-transform of x[n] is X[z]... What is the algebraic expression of z-transform of ejω0n x[n]?

  • X(Z - Z0)
  • X(e-jW0z)
  • X(ejω0z)
  • X(Z)jω0z
0 h : 0 m : 1 s