Signals and Systems – Multiple Choice Questions (MCQs)

1. 13. The region of convergence (ROC) for the Laplace Transform of a stable system always includes the:

   • A. Imaginary axis
   • B. Real axis
   • C. Origin
   • D. Right-half plane

2. 14. The final value theorem in Laplace Transform is used to find the value of a function as t tends to:

   • A. 0
   • B. ∞
   • C. 1
   • D. -1

3. 15. The Z-Transform is primarily used for the analysis of:

   • A. Continuous-time signals
   • B. Discrete-time signals
   • C. Analog signals
   • D. Random signals

4. 16. The Z-Transform of a unit impulse sequence δ[n] is:

   • A. 1
   • B. z
   • C. 1/z
   • D. z^-1

5. 17. The Z-Transform of a unit step sequence u[n] is:

   • A. z / (z-1)
   • B. 1 / (z-1)
   • C. z / (z+1)
   • D. 1 / (z+1)

6. 18. The ROC of a causal finite-duration sequence is the entire z-plane except possibly at:

   • A. z=0
   • B. z=∞
   • C. z=1
   • D. z=-1

7. 19. A system is non-causal if its impulse response h(t) is non-zero for:

   • A. t < 0
   • B. t > 0
   • C. t = 0
   • D. All t

8. 20. Which of the following is an energy signal?

   • A. u(t)
   • B. sin(t)
   • C. e^t
   • D. e^(-t)u(t)

9. 21. Which of the following is a power signal?

   • A. u(t)
   • B. e^(-t)u(t)
   • C. δ(t)
   • D. rect(t/τ)

10. 22. The period of the signal x(t) = cos(4πt) is:

    • A. 0.5 s
    • B. 1 s
    • C. 2 s
    • D. 4 s

11. 23. The period of the discrete-time signal x[n] = cos(πn/4) is:

    • A. 4
    • B. 8
    • C. π/4
    • D. 2π

12. 24. An LTI system is completely characterized by its:

    • A. Input signal
    • B. Output signal
    • C. Impulse response
    • D. Frequency response