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**

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

**previous input?**

**a) Adder**

**b) Signal Multiplier**

**c) Unit Delay**

**d) Unit Advance**

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**Q2. The total area under the probability distribution curve is**

**a) 1**

**b) 0**

**c) depend upon curve equation**

**d) 8**

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**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)**

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**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**

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**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**

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**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 **
p**t) 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**

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**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**

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**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 **

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

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**Q1. Answer: c**

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**Q2. Answer: a**

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**Q3. Answer: d**

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**Q4. Answer: a**

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**Q5. Answer: a**

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**Q6. Answer: c**

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**Q7. Answer: a**

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**Q8. Answer: d**

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**Q9. Answer: b**

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**Q10. Answer: b**

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**Q11. Answer: a**

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**Q12. Answer: c**

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**Q13. Answer: a**

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**Q14. Answer: c**

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**Q15. Answer: a**

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**Q16. Answer: d**

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**Q17. Answer: b**

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**Q18. Answer: b**

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**Q19. Answer: a**

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**Q20. Answer: a**