Q.1

The function x(t) is shown in the given figure. Even and odd parts of a unit step function ∪ (t) are respectively,

Q.2

The Laplace transform of unit ramp function starting at t = a is

Q.3

If , then x(n) series has

  • alternates 0
  • alternate 1
  • alternate 2
  • alternate -1s
Q.4

If , then x(n) series has

  • alternates 0
  • alternate 1
  • alternate 2
  • alternate -1s
Q.5

The trignometric Fourier series of an even function of time does not have

  • dc term
  • cosine term
  • sine term
  • odd harmonic terms
Q.6

The impulse response of discrete time system is x[n] = (4)n ∪[3 - n], the system is

  • casual
  • stable
  • stable and casual
  • stable and non-casual
Q.7

An ac wave with superimposed dc is symmetrical about x - axis.

  • True
  • False
Q.8

Assertion (A): L[e-at f(t)] = F(s + a)

Reason (R): In use of Laplace transform method, initial conditions may be neglected.

  • 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.9

An ac sinusoidal wave has an rms value ofV. The peak to peak value is

  • 10 V
  • 0 V
  • 14.14 V
  • 28.28 V
Q.10

The z transform of sequence x[n] = {2}

  • 2z-1 + 4z-2 + 3 + 2z+1
  • 2z-1 + 3 + 4z+1 + + 2z+2
  • 2z+1 + 3z-1 + 4z-2 + 2z-3
  • 3 + 2z-1 + 4z-2 + 2z-1
Q.11

Assertion (A): If a wave v = A1 + A2 sin ωt is applied to a pure capacitor the current wave is
i = A3 sin(ωt + 90°)

Reason (R): A capacitor presents infinite impedance to dc.

  • 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

A complex wave is 5 + 5 sin ωt. Its rms value is

  • 7.07 V
  • 5 V
  • 10 V
  • 6.12 V
Q.13

State variables which describe a system are a unique set.

  • True
  • False
Q.14

A complex wave is 5 + 5 sin ωt. Its rms value is

  • 7.07 V
  • 5 V
  • 10 V
  • 6.12 V
Q.15

For the function u(t - a) = 0 for t < a and u(t - a) = 1 fort ≥ a, the Laplace transform is

Q.16

A complex wave is 5 + 5 sin ωt. Its rms value is

  • 7.07 V
  • 5 V
  • 10 V
  • 6.12 V
Q.17

For the function u(t - a) = 0 for t < a and u(t - a) = 1 fort ≥ a, the Laplace transform is

Q.18

For the function u(t - a) = 0 for t < a and u(t - a) = 1 fort ≥ a, the Laplace transform is

Q.19

State variables which describe a system are a unique set.

  • True
  • False
Q.20

For the function u(t - a) = 0 for t < a and u(t - a) = 1 fort ≥ a, the Laplace transform is

Q.21

The inverse Laplace transform of is

  • t2 e-t
    05-29-2.png
    05-29-4.png
  • te-t
    05-29-4.png
Q.22

The inverse Laplace transform of is

  • t2 e-t
    05-29-2.png
    05-29-4.png
  • te-t
    05-29-4.png
Q.23

The inverse Laplace transform of is

  • t2 e-t
    05-29-2.png
    05-29-4.png
  • te-t
    05-29-4.png
Q.24

If Laplace transform of f(t) is F(s), then £ f(t - a) u (t - a)= 0

  • eas F(s)
  • e-as F(s)
  • - eas F(s)
  • - e -as F(s)
Q.25

A signal is sampled at Nyquist rate fs = 2f0. The function can be recovered from its samples only. If it is a

  • Periodic square wave of fundamental frequency f0
  • Triangular wave of fundamental frequency f0
  • Periodic sine wave of fundamental frequency f0
  • Unit impulse function
Q.26

Assertion (A): L[af1(t) + bf2(t)] = aF1(s) - bF2(s)

Reason (R): Initial value theroem enables us to find the value of f(t) at t = 0 directly from F(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.27

The energy of constant amplitude complex valued exponential sequence is ...

  • A2
  • ∞
  • 1
  • 0
Q.28

A voltage wave is v =sin ωt. Its average value calculated over full one cycle is

  • zero
  • 35.36 V
  • 31.85 V
  • none of the above
Q.29

Laplace transform of unit doublet is

  • 1/s
  • s2
  • s
  • none
Q.30

If f(t) = - f(- t) satisfies Drichlet conditions, then f(t) can be expanded in Fourier series containing

  • only sine terms
  • only cosine terms
  • cosine terms and constant
  • sine terms and constant
Q.31

The Laplace transform of impulse δ(t) is

  • 1
  • 1/s
  • s
  • 1/s2
Q.32

The function δ(t - b) is

  • an impulse function
  • a step function originating at t = b
  • an impulse function originating at t = b
  • none of the above
Q.33

A rectangular pulse is passed through an L.P.F. The response is a

  • triangular
  • trapezoidal function
  • sampling
  • Both (a) and (b)
Q.34

If f1 (t) and f2 (f) are two functions of time and a and b are constants, then

  • L [af1(t) + bf2(t)] = aF1(s) + bF2(s)
  • L [af1(t) + bf2(t)] = aF1(s) - bF2(s)
  • L [af1(t) + bf2(t)] =[aF1(s)]/[bF2(s]
  • None of the above
Q.35

In terms of signum function sgn(t), unit step function u(t) =

  • 1 + sgn(t)
  • 1 - sgn(t)
  • 0.5 + 0.5 sgn(t)
  • 0.5 - 0.5 sgn(t)
Q.36

The integral of a unit step function is

  • a unit impulse function
  • a unit pulse function
  • a ramp function of slope 1
  • none of the above
Q.37

An ac network has a power factor of 0.8 lagging for fundamental frequency. If the applied voltage contains thrid and fifth harmonics, the overall power factor will be

  • 0.8 lagging or less
  • more than 0.8 lagging
  • 0.8 lagging
  • less than 0.8 lagging
Q.38

Assertion (A): The number ∈ such that the probability that an error is between -∈ and + ∈ is 1 is called probable error of single obserevation.

Reason (R): The standard deviation is the arms value of the deviation from the arithmetic mean.

  • 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.39

Fourier transform of f(t) =

  • jω F(f)
  • 2pf F(f)
  • F'(f)
  • None
Q.40

Choose correct option

  • var (X + Y) = Var (X) + Var (Y)
  • var (X - Y) = Var (X) + Var (Y)
  • var (X + Y) = Var (X) x Var (Y)
  • Both (a) and (b)
Q.41

FIR filter Passes __________ Phase.

  • non-linear phase
  • linear phase
  • variable phase
  • none
Q.42

A pulse function having magnitude E and duration from t = 0 to t = a can be represented as

  • sum of two pulse functions
  • difference of two pulse functions
  • difference of two step functions each of magnitude E and one originating at t = 0 and the other at t = a
  • none of the above
Q.43

If a number of even functions are added, the resultant sum is

  • even function
  • odd funtion
  • either even or odd function
  • mixture of odd amd even functions
Q.44

If f1(t)<< F1(jω) and f2(t)↔ F2(jω), then [a1 f1(t) + a2f2(t)]↔

  • a1F1(jω) + a2F2(jω)
  • a1a2F1(jω) + F2(jω)
  • a1F1(jω) - a2F2(jω)
  • a1F1*(jω) + a2F2*(jω)
Q.45

Highest value of autocorrelation functionsinpt is

  • 50
  • zero
  • 100
  • 100/p
Q.46

For an ac sinusoidal wave, the rms value isA. For the same wave delayed byin each half cycle, the rms value is likely to be

  • 10 A
  • 7.07 A
  • 6.35 A
  • 3.5 A
Q.47

If a linear time invartant system is exicited by a pure random signal like white noise, the output of the linear system will have which of the following properties?

  • Output will be a white noise
  • Output will be periodic
  • Output will be random
  • Output will be correlated or coloured noise
Q.48

In the state equation x = AX + Bu is a n x m matrix.

  • True
  • False
Q.49

A 1 kHz sinusoidal signal is ideally sampled atsamples/sec and the sampled signal is passed through an ideal low pass filter with cut off frequencyHz. The output signal has the frequency.

  • 0 Hz
  • 0.75 kHz
  • 0.5 kHz
  • 0.25 kHz
Q.50

Principle of superposition is applicable to

  • linear systems only
  • nonlinear systems only
  • both linear and non linear system
  • linear systems and some nonlinear systems
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