Computer Hardware and Networking MCQ Quiz Hub

NETWORKING /PHYSICAL LAYER SET 2

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1. _______ encoding has a transition at the beginning of each 0 bit.




2. PCM is an example of _______ conversion.




3. If the frequency spectrum of a signal has a bandwidth of 500 Hz with the highest frequency at 600 Hz, what should be the sampling rate, according to the Nyquist theorem?




4. The Nyquist theorem specifies the minimum sampling rate to be_______.




5. Which of the following encoding methods does not provide for synchronization?




6. Which encoding method uses alternating positive and negative values for 1s?




7. Which quantization level results in a more faithful reproduction of the signal?




8. Block coding can help in _______ at the receiver.




9. In _______ transmission, a start bit and a stop bit frame a character byte.




10. In asynchronous transmission, the gap time between bytes is _______.




11. ___________ conversion involves three techniques: line coding, block coding, and scrambling.




12. ________ is the process of converting digital data to a digital signal.




13. _____ provides redundancy to ensure synchronization and inherent error detection.




14. ______ is normally referred to as mB/nB coding; it replaces each m-bit group with an n-bit group.




15. _ provides synchronization without increasing the number of bits.




16. Two common scrambling techniques are ________.




17. The most common technique to change an analog signal to digital data is called __________.




18. The first step in PCM is ________.




19. There are three sampling methods: __________.




20. ____ finds the value of the signal amplitude for each sample; ____ finds the change from the previous sample.




21. While there is (are) only _____ way(s) to send parallel data, there is (are) three subclass(es) of serial transmission.




22. In ______ transmission, we send 1 start bit (0) at the beginning and 1 or more stop bits (1s) at the end of each byte.




23. In _________ transmission, we send bits one after another without start or stop bits or gaps. It is the responsibility of the receiver to group the bits.




24. The ________ mode provides synchronization for the entire stream of bits must. In other words, it guarantees that the data arrive at a fixed rate.




25. A _________ digital signal includes timing information in the data being transmitted.




26. In decoding a digital signal, the receiver calculates a running average of the received signal power, called the _______.




27. The ________ rate defines the number of data elements sent in 1s; the ______ rate is the number of signal elements sent in 1s.




28. The signal rate is sometimes called the ____ rate.




29. The data rate is sometimes called the ___ rate.




30. In a _____ scheme, all the signal levels are on one side of the time axis, either above or below.




31. In ______ schemes, the voltages are on the both sides of the time axis. For example, the voltage level for 0 can be positive and the voltage level for 1 can be negative.




32. In _____, the level of the voltage determines the value of the bit.




33. In ______, the change or lack of change in the level of the voltage determines the value of the bit.




34. The idea of RZ and the idea of NRZ-L are combined into the ________ scheme.




35. The idea of RZ and the idea of NRZ-I are combined into the ________ scheme.




36. In _______ encoding, the duration of the bit is divided into two halves. The voltage remains at one level during the first half and moves to the other level in the second half. The transition at the middle of the bit provides synchronization.




37. In ___________ there is always a transition at the middle of the bit, but the bit values are determined at the beginning of the bit. If the next bit is 0, there is a transition; if the next bit is 1, there is none.




38. In Manchester and differential Manchester encoding, the transition at the middle of the bit is used for __________.




39. The minimum bandwidth of Manchester and differential Manchester is ____ that of NRZ.




40. In _______encoding, we use three levels: positive, zero, and negative.




41. The _____ scheme uses data patterns of size 2 and encodes the 2-bit patterns as one signal element belonging to a four-level signal.




42. The ______ scheme uses three levels (+V, 0, and -V) and three transition rules to move between the levels.




43. _____ substitutes eight consecutive zeros with 000VB0VB. a.




44. ______ substitutes four consecutive zeros with 000V or B00V.




45. ASK, PSK, FSK, and QAM are examples of ________ conversion.




46. AM and FM are examples of ________ conversion.




47. In QAM, both ________ of a carrier frequency are varied.




48. If the baud rate is 400 for a QPSK signal, the bit rate is ________ bps.




49. If the bit rate for an ASK signal is 1200 bps, the baud rate is ________.




50. If the bit rate for an FSK signal is 1200 bps, the baud rate is ________.