The GATE Grind

GATE Signals and Systems: Linear time invariant and causal systems – Previous Year Questions

26 GATE previous year questions on Linear time invariant and causal systems (Signals and Systems, Electrical Engineering) with answers and explanations, from every paper.

  1. GATE 2017 EE Q13 (1 mark, Multiple choice) – Let z(t) = x(t) * y(t), where "*" denotes convolution. Let c be a positive real-valued constant. Choose the correct expression for z(ct).
  2. GATE 2017 EE Q17 (1 mark, Multiple choice) – Consider the system with following input-output relation y[n] = (1 + (-1)n)\,x[n] where x[n] is the input and y[n] is the output. The system is
  3. GATE 2015 EE Q19 (1 mark, Numerical answer) – A moving average function is given by y(t) = 1T t-Tt u()\,d. If the input u is a sinusoidal signal of frequency 12T Hz, then in steady state, the…
  4. GATE 2015 EE Q20 (1 mark, Multiple choice) – The impulse response g(t) of a system, G, is as shown in Figure (a). What is the maximum value attained by the impulse response of two cascaded blocks…
  5. GATE 2016 EE Q18 (1 mark, Multiple choice) – Consider a continuous-time system with input x(t) and output y(t) given by y(t) = x(t) (t) This system is
  6. GATE 2016 EE Q45 (2 marks, Multiple choice) – The output of a continuous-time, linear time-invariant system is denoted by T\x(t)\ where x(t) is the input signal. A signal z(t) is called…
  7. GATE 2018 EE Q26 (1 mark, Multiple choice) – A continuous-time input signal x(t) is an eigenfunction of an LTI system, if the output is
  8. GATE 2018 EE Q43 (2 marks, Multiple choice) – Consider a system governed by the following equations dx 1(t)dt=x 2(t)-x 1(t),dx 2(t)dt=x 1(t)-x 2(t). The initial conditions are such that x 1(0)<x…
  9. GATE 2019 EE Q17 (1 mark, Multiple choice) – The symbols a and T represent positive quantities, and u(t) is the unit step function. Which one of the following impulse responses is NOT the output…
  10. GATE 2020 EE Q12 (1 mark, Multiple choice) – Which of the following is true for all possible non-zero choices of integers m,n;\ m n, or all possible non-zero choices of real numbers p,q;\ p q, as…
  11. GATE 2020 EE Q47 (2 marks, Multiple choice) – Suppose for input x(t) a linear time-invariant system with impulse response h(t) produces output y(t), so that x(t)*h(t)=y(t). Further, if x(t) * h(t)…
  12. GATE 2020 EE Q49 (2 marks, Multiple choice) – Which of the following options is true for a linear time-invariant discrete time system that obeys the difference equation: y[n]-ay[n-1]=b 0x[n]-b…
  13. GATE 2021 EE Q16 (1 mark, Multiple choice) – If the input x(t) and output y(t) of a system are related as y(t)=(0,x(t)), then the system is
  14. GATE 2021 EE Q17 (1 mark, Multiple choice) – Two discrete-time linear time-invariant systems with impulse responses h 1[n]=[n-1]+[n+1] and h 2[n]=[n]+[n-1] are connected in cascade, where [n] is…
  15. GATE 2022 EE Q46 (2 marks, Multiple choice) – Let a causal LTI system be governed by the following differential equation y(t)+14dydt=2x(t), where x(t) and y(t) are the input and output…
  16. GATE 2022 EE Q48 (2 marks, Multiple choice) – Consider the system as shown below where y(t)=x(et). The system is
  17. GATE 2023 EE Q17 (1 mark, Multiple choice) – A continuous-time system that is initially at rest is described by dy(t)dt+3y(t)=2x(t), where x(t) is the input voltage and y(t) is the output…
  18. GATE 2023 EE Q27 (1 mark, Multiple select) – Which of the following statement(s) is/are true?
  19. GATE 2023 EE Q31 (1 mark, Numerical answer) – For the signals x(t) and y(t) shown in the figure, z(t)=x(t)*y(t) is maximum at t=T 1. Then T 1 in seconds is (Round off to the nearest integer).
  20. GATE 2023 EE Q36 (2 marks, Multiple choice) – The magnitude and phase plots of an LTI system are shown in the figure. The transfer function of the system is
  21. GATE 2024 EE Q15 (1 mark, Multiple choice) – Suppose signal y(t) is obtained by the time-reversal of signal x(t), i.e., y(t)=x(-t), -<t<. Which one of the following options is always true for the…
  22. GATE 2024 EE Q37 (2 marks, Multiple choice) – The input x(t) and the output y(t) of a system are related as y(t)=e-t -te x()\,d,-<t<. The system is
  23. GATE 2024 EE Q38 (2 marks, Multiple choice) – Consider the discrete-time systems T 1 and T 2 defined as follows: \T 1x\[n]=x[0]+x[1]++x[n] \T 2x\[n]=x[0]+12x[1]++12nx[n] Which one of the following…
  24. GATE 2025 EE Q20 (1 mark, Multiple choice) – Consider a discrete-time linear time-invariant (LTI) system S, where y[n]= S\x[n]\. Let S\[n]\=cases1,&n\0,1,2\\\0,&otherwisecases where [n] is the…
  25. GATE 2025 EE Q40 (2 marks, Multiple choice) – Let continuous-time signals x 1(t) and x 2(t) be x 1(t)=cases1,&t[0,1]\\2-t,&t[1,2]\\0,&otherwisecasesand x…
  26. GATE 2025 EE Q42 (2 marks, Multiple choice) – The continuous-time unit impulse signal is applied as an input to a continuous-time linear time-invariant system S. The output is observed to be the…