Q.1

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

Q.2

The Laplace transform of the waveform shown in the below figure is

Q.3

The Laplace transform of the waveform shown in the below figure is

Q.4

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

Q.5

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

Q.6

If , then x(n) series has

  • alternates 0
  • alternate 1
  • alternate 2
  • alternate -1s
Q.7

If , then x(n) series has

  • alternates 0
  • alternate 1
  • alternate 2
  • alternate -1s
Q.8

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

  • dc term
  • cosine term
  • sine term
  • odd harmonic terms
Q.9

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.10

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

  • True
  • False
Q.11

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.12

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.13

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.14

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.15

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

  • 7.07 V
  • 5 V
  • 10 V
  • 6.12 V
Q.16

State variables which describe a system are a unique set.

  • True
  • False
Q.17

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

  • 7.07 V
  • 5 V
  • 10 V
  • 6.12 V
Q.18

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

Q.19

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

  • 7.07 V
  • 5 V
  • 10 V
  • 6.12 V
Q.20

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

Q.21

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

Q.22

State variables which describe a system are a unique set.

  • True
  • False
Q.23

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

Q.24

The inverse Laplace transform of is

  • t2 e-t
    05-29-2.png
    05-29-4.png
  • te-t
    05-29-4.png
Q.25

The inverse Laplace transform of is

  • t2 e-t
    05-29-2.png
    05-29-4.png
  • te-t
    05-29-4.png
Q.26

The inverse Laplace transform of is

  • t2 e-t
    05-29-2.png
    05-29-4.png
  • te-t
    05-29-4.png
Q.27

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.28

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.29

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.30

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

  • A2
  • 1
  • 0
Q.31

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.32

Laplace transform of unit doublet is

  • 1/s
  • s2
  • s
  • none
Q.33

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.34

The Laplace transform of impulse δ(t) is

  • 1
  • 1/s
  • s
  • 1/s2
Q.35

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.36

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

  • triangular
  • trapezoidal function
  • sampling
  • Both (a) and (b)
Q.37

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.38

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.39

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.40

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.41

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.42

Fourier transform of f(t) =

  • jω F(f)
  • 2pf F(f)
  • F'(f)
  • None
Q.43

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.44

FIR filter Passes __________ Phase.

  • non-linear phase
  • linear phase
  • variable phase
  • none
Q.45

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.46

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.47

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.48

Highest value of autocorrelation functionsinpt is

  • 50
  • zero
  • 100
  • 100/p
Q.49

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.50

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
0 h : 0 m : 1 s