# Signals and Systems 6

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject: Signals and Systems 6

Part 6: List for questions and answers of Signals and Systems

Q1. Which block of the discrete time systems requires memory in order to store the

previous input?

b) Signal Multiplier

c) Unit Delay

Q2. The total area under the probability distribution curve is

a) 1

b) 0

c) depend upon curve equation

d) 8

Q3. The output of a linear system for any input can be computed in which of the following ways?

a) Only by summation of inpulse response by convolution integral

b) Only by summation of step response by superposition integral

c) Neither a nor b

d) Either (a) or (b)

Q4. If a function f(t) is an odd, function, its Fourier series

a) Contains only sine terms

b) Contains only cosine terms

c) Contains a constant and sine terms

d) Contains a constant and cosine

Q5. A system has poles at 0.01 Hz, 1 Hz and 80 Hz, zeros at 5 Hz, 100 Hz and 200 Hz. The approximate phase of the system response at 20 Hz is

a) -90°

b) 0°

c) 90°

d) -180°

Q6. Which one is correct option about ROC?

a) ROC does not contain any pole

b) ROC of finite duration sequence is entire plane expect z = 0, z = 8

c) a and b

d) Only a

Q7. Final value theorem is used to find

a) Steady state value of system output

b) Initial value of output

c) Transient beaviour of output

d) None of these

Q8. The tree selected for the formation of state equations contains

a) All voltage sources

b) All capacitors

c) All inductors and current sources

d) All voltage sources and maximum number of capacitors

Q9. An impulse train is

a) A number of pulses

b) A number of pulses spaced from each other

c) A number of pulses all originating together

d) None of the above

Q10. For formation of state equations, the inductors and current sources

a) Should be in tree

b) Should be in cotree

c) May be in tree or cotree

d) Should be in both tree and cotree

Q11. The power in the signal s(t) = 8 cos (20   p –  p/2) + 4 sin (15  pt) is

a) 40

b) 41

c) 42

d) 82

Q12. The peak factor is

a) rms value/peak value

b) rms value/average value

c) peak value/rms value

d) peak to peak value/rms value

Q13. If f(t) is an even function, the coefficients Fn in the exponential form of Fourier series

a) Are real

b) Are imaginary

c) Are complex

d) May be real or imaginary

Q14. The theoretical power of white noise is

a) Zero

b) Finite

c) Depend upon frequency of signal

d) Infinite

Q15. The area of an impulse is

a) 1

b) 0

c) 8

d) any finite value

Q16. e^-3t is a

a) Energy signal

b) Power signal

c) Both (a) and (b)

d) None

Q17. The energy of highest value of Autocorrelation of a function 100 cos 50 p t is

a) 50

b) 10

c) 200

d) zero

Q18. If u is input, y is output and a, b are constants, the system y = au + b

a) Is linear

b) Is nonlinear

c) May be linear or nonlinear depending on values of a and b

d) May be linear or nonlinear depending on value of u

Q19. Auto correlation function

a) Is an even function of t

b) Is an odd function of t

c) May be an even or odd function of t

d) Is both an odd and even function of t

Q20. In a oscillator, a sine wave generator starts at t = 0. It consist of

a) Pure sine wave

b) Pure cosine wave

c) Unity for t > 0

d) 2 (t) – 1

Part 6: List for questions and answers of Signals and Systems