Digital Signal Processing Multiple Choice Questions
Digital Signal Processing Multiple Choice Questions 1) The product of two odd signals is: Odd Even Both (a) and (b) Zero Answer: (b) Even Description: Let x1(n) and x2(n) be the two signals. If both these signals are odd, x1(-n) = - x1(n) and x2(-n) = - x2(n) If a signal is even, x(-n) = x(n) x(-n) = x1(-n) . x2(-n) x(-n) = - x1(n). - x2(n) x(-n) = x1(n). x2(n) It means that x(-n) = x(n), which is even. Hence, the product of two odd signals is even. 2) The system given by y(n) = x(n) + 1/x(n - 1) is: Linear Causal Both (a) and (b) None of the above Answer: (b) Causal Description: Step 1: The system is causal if its output depends only on the past and present inputs. Let's check its causality. We will check the value of y(n) for different values of n. For, n= 0, y(0) = x(0) + 1/x(-1) n = 1, y(1) = x(1) + 1/x(0) Thus, the system is causal. Step 2: The system that satisfies the superposition theorem can be classified as the linear system. Y1(n) = x1(n) + 1/x1(n - 1) Y2(n) = x2(...