Data Communication and Networking – Digital to Digital Encoding Methods – Unipolar / Bipolar / Polar MCQs

This set of Data communication and Networking Multiple Choice Questions and Answers (MCQs) focuses on “Digital to Digital Encoding Methods- Unipolar – Bipolar – Polar”. 

1. Unipolar
2. Bipolar
3. Polar
   1. NRZ
      1. NRZ-L
      2. NRZ-I
   2. RZ
   3. Biphase
      1. Manchester
      2. Differential Manchester

PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE

1. In _______ encoding one amplitude represents a 1 bit and zero amplitude represents a 0 bit (or vice versa).

• unipolar
• polar
• bipolar
• b and c

A. unipolar

2. In _______ encoding positive and negative amplitudes represent the bits

• unipolar
• polar
• bipolar
• b and c

B. polar

3. In _______ encoding positive, negative, and zero amplitudes represent the bits

• unipolar
• polar
• bipolar
• b and c

C. bipolar

4. A digital signal has its 0 bits represented by 0 volts and its 1 bit represented by 5 volts. This is _______ encoding.

• unipolar
• polar
• bipolar
• b and c

A. unipolar

5. A digital signal has its 0 bits represented by 0 volts and its 1 bit represented by -5 volts or 5 volts. This is _______ encoding

• unipolar
• polar
• bipolar
• b and c

C. bipolar

6. A digital signal has its 0 bits represented by -5 volts and its 1 bit represented by 5. This is _______ encoding

• unipolar
• polar
• bipolar
• b and c

B. polar

7. The DC component is a serious problem for _______ encoding

• unipolar
• polar
• bipolar
• b and c

A. unipolar

8. Unipolar encoding has a DC component because the average _______ of the signal is nonzero

• amplitude
• frequency
• phase
• period

A. amplitude

9. NRZ-L is a _______ encoding method.

• unipolar
• polar
• bipolar
• none of the above

B. polar

10. NRZ-I is a _______ encoding method.

• unipolar
• polar
• bipolar
• none of the above

B. polar

11. RZ is a _______ encoding method.

• unipolar
• polar
• bipolar
• none of the above

B. polar

12. Manchester encoding is a _______ encoding method

• unipolar
• polar
• bipolar
• none of the above

B. polar

13. Differential Manchester encoding is a _______ encoding method.

• unipolar
• polar
• bipolar
• none of the above

B. polar

14. AMI is a _______ encoding method

• unipolar
• polar
• bipolar
• none of the above

C. bipolar

15. B8ZS is a _______ encoding method.

• unipolar
• polar
• bipolar
• none of the above

C. bipolar

16. HDB3 is a _______ encoding method.

• unipolar
• polar
• bipolar
• none of the above

C. bipolar

17. _______ encoding is superior to _______ encoding because the problem of the DC component is alleviated

• Unipolar; polar
• Polar; bipolar
• Polar; unipolar
• Unipolar; bipolar

C. Polar; unipolar

18. Ethernet LANs use _______ encoding

• RZ
• Manchester
• differential Manchester
• NRZ-I

B. Manchester

19. Token Ring LANs use _______ encoding

• RZ
• Manchester
• differential Manchester
• NRZ-I

C. differential Manchester

20. In _______ encoding the transition between a positive and a negative voltage represents a 1 bit

• NRZ-I
• NRZ-L
• Manchester
• differential Manchester

A. NRZ-I

21. In _______ encoding halfway through each bit interval, the signal returns to zero.

• NRZ-I
• NRZ-L
• RZ
• Manchester

C. RZ

22. RZ encoding requires _______ signal change(s) to encode one bit.

• no
• one
• two
• three

C. two

23. Manchester and differential Manchester encoding are both types of _______ encoding

• unipolar
• NRZ
• biphase
• bipolar

C. biphase

24. Which of the following is not a type of bipolar encoding?

• AMI
• RZ
• B8ZS
• HDB3

B. RZ

25. The DC component problem is handled in AMI through _______

• transitions at the beginning of each bit interval
• transitions at the middle of each bit interval
• alternate positive and negative amplitudes for the 1 bits
• alternate positive and negative amplitudes for the 0 bits

C. alternate positive and negative amplitudes for the 1 bits

26. The DC component problem is handled in pseudoternary AMI through _______

• transitions at the beginning of each bit interval
• transitions at the middle of each bit interval
• alternate positive and negative amplitudes for the 1 bits
• alternate positive and negative amplitudes for the 0 bits

D. alternate positive and negative amplitudes for the 0 bits

27. The synchronization problem for long streams of 1s is handled in AMI through _______.

• transitions at the beginning of each bit interval
• transitions at the middle of each bit interval
• alternate positive and negative amplitudes for the 1 bits
• alternate positive and negative amplitudes for the 0 bits

C. alternate positive and negative amplitudes for the 1 bits

28. AMI is an acronym for _______.

• asynchronous mark inversion
• alternate mark inversion
• active mapped inversion
• alternate mask inversion

B. alternate mark inversion

29. _______ is a variation of AMI.

• B8ZS
• HDB3
• UB40
• a and b

D. a and b

30. _______ is an attempt to synchronize long strings of 0s

• B8ZS
• HDB3
• UB40
• a and b

D. a and b

31. In _______ encoding, anytime there are eight or more consecutive 0 bits, violations are deliberately introduced

• B8ZS
• HDB3
• HDLC
• B4ZS

A. B8ZS

32. In _______ encoding, anytime there are four or more consecutive 0 bits, violations are deliberately introduced

• B8ZS
• HDB3
• HDLC
• B4ZS

B. HDB3

33. _______ encoding is used in North America to provide synchronization of strings of 0s.

• B8ZS
• HDB3
• HDLC
• B4ZS

A. B8ZS

34. _______ encoding is used in Europe and Japan to provide synchronization of strings of 0s

• B8ZS
• HDB3
• HDLC
• B4ZS

B. HDB3

35. In B8ZS encoding, a string of eight consecutive 0s produces _______

• one violation
• two violations
• three violations
• any of the above

B. two violations

36. In HDB3 encoding, a string of four consecutive 0s produces _______.

• one violation
• two violations
• three violations
• any of the above

A. one violation