1. Consider a single-tone AM signal with m(t) = 3 cos 400mt and c(t) = 10 cos(10000mt). Let k, = 0.2. Find power in s(t)= (1+ kam(t)) c(t). (i) Calculate AM efficiency defined as NAM (ii) Plot the spectrum S(f). Power in Side tones Total Power in s(t) sin 400xt 2. Consider an AM signal with m(t) 212 spectra of (1) M(f) (ii) C(f) and (iii) S(f). M x 100. and e(t) = 10 cos(10000 t). Let ka -0.2. Plot the 3. Let the signal (t) = A. [1+kum(t)] cos 2n fet be fed to a nonlinear device that produces an output v(t)= a(t) + vi (t). Find the conditions for which the message m(t) my be recovered from v (t). 4. Problem 3-2 from the textbook. 5. Show that a synchronous demodulator can also demodulate an AM signal. Let s(t)= {1+kam(t)) c(t). Assume that cos 2a fet is available in a local oscillator. By multiplying s(t) with cos 2n fet, and by filtering we can get m(t). Draw a schematic for this method and explain.