# Question one (10 marks): Circle the most correct answer of the following: 1) For a given AM wave, th

Question one (10 marks): Circle the most correct answer of the following: 1) For a given AM wave, the modulation index should not exceed: a) 0.8 b) 0.5 c) 1 d) O 2) For an AM wave, the maximum amplitude is found to be 9V, while the minimum amplitude is found to be 3. What is the modulation index? b) 0.75 c) 0.5 d) 0.25 3) A signal wave has a frequency of 12KHz is modulated with a carrier wave of frequency 2.51 MHz. The upper and lower side band frequencies are: a) 2522 KHz and 2498 KHz b) 2512 Hz and 2508 KHz c) 2522 KHz and 2488 KHz d) 2502 KHz and 2498 KHz e) None of the above 4) In a Double Side Band-Large Carrier (DSB-LC) AM transmission system, if the modulation index is doubled, then the ratio of the total sidebands power to the carrier power increases by a factor of: a) 1 b) 2 c) 4 d) 16 e) None of the above 5) The Nyquist rate of the signal g(t) = sinc(200t)+ sinc(150t) is : a) 200 Hz b) 300 Hz c) 600 Hz d) 500 Hz e) 150 Hz 6) The Nyquist rate of the signal g(t) = sin(3000t) +cos”(2×1000) + cos (4000) is: a) 1 KHz b) 2 KHz c) 8 KHz 4 KHz 6 KHz 7) What is the forms of pulse-time in the figure below: ummm a) b) c) d) PAM PPM PDM PCM 8) Consider a compact disc that uses pulse-code modulation to record audio signals whose bandwidth W-10Khz and uses 256 level uniform Quantization. Determine the minimum permissible bit rate. 80kbbs b) 180kbbs c) 160kbbs d) 90kbbs e) None of the above 9) Reconstruction filter used to recover the original signal from its uniformly sampled version is: a) Low-pass filter with a cutoff frequency – W b) Low-pass filter with a cutoff frequency-2W c) High-pass filter with a cutoff frequency – W d) Band-pass filter with a cutoff frequency of e) Band-pass filter with a cutoff frequency – W 10) A signal x(t) = 100 cos (24x x 10&#39;t) is ideally sampled with a sampling period of 45.45 u sec and then passed through an ideal low pass filter with cut off frequency of 15 kHz Which of the following frequencies are present at the filter output? a) 12 kHz only b) 8 kHz only c) 12 kHz and 10 kHz d) 12 kHz and 8 kHz e) 12 kHz and 10 kHz and 8 kHz