21. 4D-PAM5 is of the following encoding types a. line b. block b. NRZ d. more that one answer are correct 22. In Bipbasescheme a. no baseline wandering is a disadvantage and lower signal rate is an advantage b. no baseline wandering is an advantage and no DC component is a disadvantage c. higher signal rate is an advantage and DC component is a disadvantage d. no DC component is an advantage and higher signal rate is a disadvantage 23. Which encoding method uses alternating positive and negative values for 1s? a. NRZ-I b. RZ C. AMI d. Manchester 24. In a coding scheme the following 10-bit sample is given: (4 pts) 1001110100 What would be the average bandwidth needed for a data rate of 100kbps for this scheme? Note: normalized bandwidth-f(#of changes in the 10-bit sample)/N (#of bits in the sample) a. 10 KHZ b. 50 KHZ c. 100 KHZ d. None of the above 25. The SNRu,in a channel is 50dB and the bit rate is 80Kbps for transmitting a digitized form of an analog signal for recovering the analog signal on the receiver side. What is the most likely range of frequencies in the analog signal which has been digitized? (4 pts) Note: SXR4u-6.02nb + 1.76 dB-) &_ #of bits/sample The sampling rate of an analog signal must be twice the highest frequency in that signal for complete recovery of analog signal from digitized signal. a. 2KHZ to 5KHZ b. 10KHZ to 15KHZ c. 40KHZ to 50KHZ d. 80KHZ to 90KHZ 26. In Block coding compared to biphase and NRZ-I respectively the a. signal rate increases but it offers better synchronization b. signal rate decreases but degrades synchronization c. signal rate decreases and synchronization degrades d. signal rate decreases and it offers better synchronization 27. The idea of RZ and the idea of NRZ-I are combined into the scheme a. Manchester b. Differential Manchester c. MLT-3 d. More than one answer in a, b, and c are correct