KTU B.Tech S4 model Questions Signals and Systems

**KTU B.Tech S4 model Questions Signals & Systems**

**MODEL QUESTION PAPER Prepared by **__ktubtechquestions.com__

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**FOURTH SEMESTER B.TECH DEGREE EXAMINATION **

** May/June 2017**

**EC202 Signals and Systems**

**EC202 Signals and Systems**

**Time:** **3 Hrs Marks: 100**

__PART A__

( Answer **any One from 1 and 2**. Q.No: 3 is Compulsory )

**a)**Define the following continuous functions.

(i) Signum function (ii) Sync function (**3 mark)**

**b)** Plot the signals

** **

**OR**

**2. a)** Determine the odd and even part of the signal, x(t) = (1+t3 ) cos3 10t**( 2 marks)**

** b)** Check whether the following signals are Energy signals or power, Also determine energy / power.

**(i)** x(t) = A cos ( ω0t +θ)

**(ii)** x(t) = u(t+1) **(8 Marks)**

** **

**3. (a)** Determine the convolution of signals x1(t) = cost u(t), x2(t) = tu(t).**(4 Marks) **

**(b)**Plot the signals **(6 marks)**

** (c)** Graphically determine the convolution of signals **(10 Marks)**

__ PART B__

(Answer **any One from 4 and 5**. Q.No: 6 is Compulsory)

**4 i)** Find LT of x(t) = e2t ( u(t) – u(t-4) ) **(4 Marks)**

** ii)**Find the complex exponential Fourier series representation of the signal given by x(t) = cos ω0t.

**(6 marks)**

**OR**

**5 i)** Plot Magnitude spectrum and Phase spectrum of the signal x(t) = e –at u(t) . **(6 marks)**

** ii)** Write down the time convolution property of Fourier Transform **(4 marks)**

**6 i)** Verify initial value theorem for the function x(t) = 2- e 5t **(5 marks)**

** ii)** State and prove convolution theorem of Fourier series.** (5 marks**)

** iii)** Write down the time convolution property of Fourier Transform **(5 marks**)

** iv)** Expand the function x(t) shown, by trigonometric Fourier series over interval (0,1)**(5 Marks)**

__PART C__

(Answer **any One from 7 and 8**. Q.No: 9 is Compulsory)

**7 i)** What are the different sampling techniques? Explain in detail. **(7 marks)**

** ii)**Write a note on Discrete Hilbert Transform. **(3 marks)**

**OR**

**8** ** i)** Determine Z transform and ROC of the signal x(n) = u(n) – u (n-8)**(6 Marks)**

** ii)** Find DTFT of the sequence x(n) = -a n u(-n-1) (**4Marks)**

**9 i)** A band limited signal x(t) is sampled by a train of pulses of width τ and period T. Determine the spectrum of sampled signal and sketch it. Also find expression for sampled signal** (10 marks)**

** ii)** Find the Inverse Z transform of the signals **(10 marks)**

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