======================================================================= ss15_B01-1 (DT Signals by Impulses) ----------------------------------------------------------------------- SS2-6: Representation of DT Signals x[n] = ... + x[1] delta[n+1] + x[0] delta[n] + x[-1] delta[n-1] + ... (a) True or (b) False (b) False ======================================================================= ss15_B01-2 (DT Unit Impulse Response & Convolution Sum) ----------------------------------------------------------------------- SS2-12: Convolution of x[n] & h[n] If a system is linear and its impulse response for delta[n-k] is h_k[n], then for any input x[n], the output y[n] = x[n]*h_k[n]. (a) True or (b) False (b) False ======================================================================= ss15_B01-3 (Ex 2.1-2.2) ----------------------------------------------------------------------- SS2- ======================================================================= ss15_B01-4 (Ex 2.3-2.5) ----------------------------------------------------------------------- SS2- ======================================================================= ss15_B02-1 (CT LTI Systems) ----------------------------------------------------------------------- SS2- ======================================================================= ss15_B02-2 (CT Impulse Response & Convolution Integral) ----------------------------------------------------------------------- SS2-34: LTI and Convolution For an CT LTI system denoted by h(t), and any input signal x(t) and its corresponding output y(t), which of the following statements is/are true? (a) x(t) = \int_{-\infty}^{+\infty} { \delta(\tau)} { x(t-\tau)} d \tau (b) h(t) = \int_{-\infty}^{+\infty} { h(\tau)} { \delta(t-\tau)} d \tau (c) y(t) = \int_{-\infty}^{+\infty} { h(\tau)} { x(t-\tau)} d \tau (a), (b), (c) ======================================================================= ss15_B02-4 (Convolution Sum and Integral) ----------------------------------------------------------------------- SS2-41: Signals and Systems For x(t), y(t), h(t) used to describe the input, output and system, the variable t in x(t) and y(t) denote absolute (world ) time and variable t in h(t) denotes the relative time, i.e., the influence/affecting time instance of the input x(t) on the system. (a) True or (b) False (a) True ======================================================================= ss15_B03-2 (Properties - Commutative Distributive) ----------------------------------------------------------------------- SS2-45: Commutative Which one(s) is(are) True? (a) \sum_{r=-\infty}^{+\infty} h[r] x[n-r] = \sum_{r=+\infty}^{-\infty} x[n-r] h[-r] (b) \sum_{r=-\infty}^{+\infty} h[r] x[n-r] = \sum_{r=+\infty}^{-\infty} x[n-r] h[r] (c) \int_{+\infty}^{-\infty} x(\sigma-t) h(-\sigma) (d \sigma) = \int_{-\infty}^{+\infty} x(t-\sigma) h(\sigma) d \sigma (d) \int_{+\infty}^{-\infty} x(t-\sigma) h(\sigma) (-d \sigma) = \int_{-\infty}^{+\infty} x(t-\sigma) h(\sigma) d \sigma (b) (d) ----------------------------------------------------------------------- SS2-46: Commutative Distributive Associative Which one(s) is(are) True? (a) x(t)*( h_1(t) + h_2(t) ) = x(t)*h_1(t) + x(t)*h_2(t) (b) (x_1[n] + x_2[n] )*h_1[n] = x_1[n]*h[n] + x_2[n]*h[n] (c) x(t)*( h(t)*y(t) ) = ( x(t)*(h(t) )*y(t)) (a) (b) (c) ======================================================================= ss15_B03-3 (Properties - Associative Memory Invertible) ----------------------------------------------------------------------- SS2- ======================================================================= ss15_B03-5 (Properties - Causality) ----------------------------------------------------------------------- SS2- ======================================================================= ss15_B03-6 (Stability Ex-2.13 Impulse Step Responses) ----------------------------------------------------------------------- SS2-51-57-60: Memory Causal Stable For an LTI system by h[n] = (0.8)^n u[n+3], then the system is: (a) memoryless (b) causal (c) stable ======================================================================= ss15_B04-1 (Linear Const Coeff Diff Eqn) ----------------------------------------------------------------------- SS2-81: Output Input Impulse Response When x(t) = \delta(t) and y(t) = f(t), then, when x(t) = g(t), then y(t) = ? y(t) = f(t) * g(t) ======================================================================= ss15_B05-1 (Singularity Functions Ex-2.16) ----------------------------------------------------------------------- SS2-72: Unit Doublets Which one(s) is(are) true? (a) y(t) = x(t)*u_1(t): y(t) is the derivative of x(t). (b) y(t) = x(t)*u_{-1}(t): y(t) is the integral of x(t). (c) x(t) = x(t)*u_0(t). (d) u_{-2}(t) = u(t) * u(t). a, b, c, d ======================================================================= ----------------------------------------------------------------------- SS2- ======================================================================= ----------------------------------------------------------------------- SS2- ======================================================================= ----------------------------------------------------------------------- SS2-