Q.1

Two function g1(t) and g2(t) with correlation of 6 has average power of 4 and 5 respectively. The power of g1(t) + g2(t) is

  • 9
  • 21
  • 3
  • 15
Q.2

An impulse function consist of

  • pure dc
  • pure a.c
  • entire frequency range with constant phase
  • infinite bandwidth with linear phase vaariations
Q.3

The ROC of sequence in the Z.T. of sequence x[n] = an ∪ [n] is

  • z > a
  • z < a
  • |z| > a
  • |z| < a
Q.4

In Laplace transform, multiplication by e-at in time domain becomes

  • translation by a in s domain
  • translation by (-a) in s domain
  • multiplication by e-as in s domain
  • none of the above
Q.5

Z transform is a non-linear operation.

  • True
  • False
Q.6

As per time displacement theorem in Laplace transformation, displacement in the time domain by T becomes

  • division by s in the s domain
  • division by e-sT in the s domain
  • multiplication by s in the s domain
  • multiplication by e-sT in the s domain
Q.7

The range of value "a" for which system will be stable. If impulse response of DT system is = an ∪[n]

  • a > 1
  • a < 1
  • 1 < a < ∞
  • -1 < a < 1
Q.8

The DTFT of x(n) = δ(n) will be

  • 1
  • 0
  • ∞
  • not defined
Q.9

The Laplace transform of f(t) is

  • none of the above
Q.10

Energy density spectrum of x[n] = an∪[n] for -1 < a < + 1 is

Q.11

Energy density spectrum of x[n] = an∪[n] for -1 < a < + 1 is

Q.12

If the poles of H(z) are at

  • z = 1 and z = 3
    09-113-3.png
  • z = -1 and z = -3
Q.13

If the poles of H(z) are at

  • z = 1 and z = 3
    09-113-3.png
  • z = -1 and z = -3
Q.14

A rectangular pulse train s(t) is shown in figure is convolved with the signal cos2(4p x 103t). The convolved signal will be a

  • DC
  • 12 kHZ sinusoidal
  • 8 kHZ sinusoidal
  • 14 kHZ sinusoidal
Q.15

Choose the function f(t), - ∞ < t < + ∞, for which a Fourier series cannot be defined

  • 3 sin (25t)
  • 4 cos (20t + 3) + 2 sin (10t)
  • exp - | t | sin 25 t
  • 1
Q.16

A signal f(t) = cos 10pt + 3 cos 4pt is instantaneously sampled. The maximum allowable value of sampling interval Ts in sec is

  • 1 / 4 sec
  • 1 / 8 sec
  • 1 / 8p sec
  • 1 / 10 sec
Q.17

A signal f(t) = cos 10pt + 3 cos 4pt is instantaneously sampled. The maximum allowable value of sampling interval Ts in sec is

  • 1 / 4 sec
  • 1 / 8 sec
  • 1 / 8p sec
  • 1 / 10 sec
Q.18

If autocorrelation sequence is Rc(n) = then what will be energy of sequence?

  • 2
  • 24
  • 3
  • 288
Q.19

If autocorrelation sequence is Rc(n) = then what will be energy of sequence?

  • 2
  • 24
  • 3
  • 288
Q.20

The range of value "a" for which system will be stable. If impulse response of DT system is = an ∪[n]

  • a > 1
  • a < 1
  • 1 < a < ∞
  • -1 < a < 1
Q.21

Auto correlation for t = 0 is equal to

  • average power S of waveform
  • square of average power S of waveform
  • half of average power S of waveform
  • square root of average power S of waveform
Q.22

Fourier transform of f(t) =

  • jω F(f)
  • 2pf F(f)
  • F'(f)
  • None
Q.23

The range of value "a" for which system will be stable. If impulse response of DT system is = an ∪[n]

  • a > 1
  • a < 1
  • 1 < a < ∞
  • -1 < a < 1
Q.24

The DTFT of x(n) = δ(n) will be

  • 1
  • 0
  • ∞
  • not defined
Q.25

A voltage wave containingthird harmonic is applied to a scries R-L circuit. The percentage third harmonic content in the current wave will be

  • more than 10%
  • 10% or less than 10%
  • less than 10%
  • 10% or more or less
Q.26

If f(t) ↔ F(jω), and f(t) is real, then

Q.27

The Laplace transform of f(t) is

  • none of the above
Q.28

The Laplace transform of f(t) is

  • none of the above
Q.29

If the poles of H(z) are at

  • z = 1 and z = 3
    09-113-3.png
  • z = -1 and z = -3
Q.30

Choose the function f(t), - ∞ < t < + ∞, for which a Fourier series cannot be defined

  • 3 sin (25t)
  • 4 cos (20t + 3) + 2 sin (10t)
  • exp - | t | sin 25 t
  • 1
Q.31

A signal f(t) = cos 10pt + 3 cos 4pt is instantaneously sampled. The maximum allowable value of sampling interval Ts in sec is

  • 1 / 4 sec
  • 1 / 8 sec
  • 1 / 8p sec
  • 1 / 10 sec
Q.32

If v(t) is a time varying voltage, is

  • initial current
  • initial voltage
  • initial charge
  • initial flux leakages
Q.33

In the given figure 15.6 shows a series, R - C circuit fed by a current source i(t). There is an initial voltage v0. across the capacitor. The system

  • is linear
  • is non linear
  • may be linear or non linear
  • is linear only if v0 is zero
Q.34

The DTFT of x(n) = δ(n) will be

  • 1
  • 0
  • ∞
  • not defined
Q.35

If f(t) ↔ F(jω), and f(t) is real, then

Q.36

The solution of state equations using Laplace transform is

  • x(t) = φ(t) x(0) + L-1 [φ(s) Bu(s)]
    05-42-3.png
  • x(t) = φ(s) x(0) + L-1 [φ(s) Bu(s)]
    05-42-3.png
  • x(t) = eAt X(0) + eA(t-t) Bu(t)dt
  • Both (a) and (b)
Q.37

If a signal g(t) has energy E, then the energy of the signal g(2t) is equal to ...

  • E/2
  • E/4
  • E
  • 2E
Q.38

If f(k) ↔ F(z), then kn fk ↔

  • [F(z)]n
    14-196-2.png
    14-196-4.png
  • [F(z)]1/n
    14-196-4.png
Q.39

The Laplace transform of f(t) is

  • none of the above
Q.40

The period of the function cos is

  • 8s
    12-158-4.png
  • 4s
    12-158-4.png
Q.41

If £[f(t)] = F(s), then £[f(t - T)] =

  • est F(s)
    13-168-3.png
    13-168-4.png
  • e-st F(s)
    13-168-3.png
    13-168-4.png
Q.42

If autocorrelation sequence is Rc(n) = then what will be energy of sequence?

  • 2
  • 24
  • 3
  • 288
Q.43

If v(t) is a time varying voltage, is

  • initial current
  • initial voltage
  • initial charge
  • initial flux leakages
Q.44

If f(t) ↔ F(jω), and f(t) is real, then

Q.45

The solution of state equations using Laplace transform is

  • x(t) = φ(t) x(0) + L-1 [φ(s) Bu(s)]
    05-42-3.png
  • x(t) = φ(s) x(0) + L-1 [φ(s) Bu(s)]
    05-42-3.png
  • x(t) = eAt X(0) + eA(t-t) Bu(t)dt
  • Both (a) and (b)
Q.46

The impulse response h[n] of a linear time invariant system is given as

If the input to the above system is the sequence ejpn/4, then the output is

  • 42 ejpn/4
  • 42 e- jpn/4
  • 4epn/4
  • -4epn/4
Q.47

If f(k) ↔ F(z), then kn fk ↔

  • [F(z)]n
    14-196-2.png
    14-196-4.png
  • [F(z)]1/n
    14-196-4.png
Q.48

The period of the function cos is

  • 8s
    12-158-4.png
  • 4s
    12-158-4.png
Q.49

The period of the function cos is

  • 8s
    12-158-4.png
  • 4s
    12-158-4.png
Q.50

Auto correlation for t = 0 is equal to

  • average power S of waveform
  • square of average power S of waveform
  • half of average power S of waveform
  • square root of average power S of waveform
0 h : 0 m : 1 s