Module 23b

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NEETS MODULE 23 MAGNETIC RECORDING ASSIGNMENT 2

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1. Magnetic tape recorders use what type of electronic circuitsto record and reproduce analog input signals?

A. Continuous waveB. Frequency modulationC. Amplitude modulationD. Both B and C above *

2. Direct record electronics record input signals onto magnetic

tape just as they appeared at the recorder's input.

A. True *B. False

3. Which part of the direct record electronics component takesthe input signal and the bias signal and mixes themtogether?

A. Input pre-amplifier circuitB. Bias sourceC. Summing network *D. Head driver circuit

4. Which part of the direct record electronics amplifies thesignal from the summing network and sends it to the record

head?

A. Bias source circuitB. Head driver circuit *C. Input pre-amplifier circuitD. Low-pass filter circuit

5. The pre-amplifier circuit of the direct reproduce electronicsdoes which of the following functions?

A. Amplifies the reproduced signalB. Removes the bias signalC. Both A and B above *D. Corrects phase errors

6. What circuit in the direct reproduce electronics takes thepre-amplified signal and fixes frequency response problemsthe reproduce magnetic head may have caused?

A. Equalization and phase correction circuit *B. Output amplifier circuitC. Head driver circuitD. Summing network

7. What circuit of the direct-reproduce electronics serves as animpedance matcher?

A. Pre-amplifier circuitB. Output amplifier circuit *C. Equalization and phase correction circuitD. Head driver circuit

8. How do FM record electronics process the incoming signalbefore sending it to the record head?

A. A high frequency, negative bias is added to the inputsignal

B. A summing network mixes the bias and input signalC. Both 1 and 2 aboveD. The input signal is frequency modulated onto the carrier

frequency of a record oscillator *

9. In the FM record electronics, what is the output of the recordoscillator circuit?

A. The demodulated input signalB. The frequency modulated carrier signal *C. A clean input signal with the negative bias removedD. A combined input signal and equalization signal

10. Pre-amplifier circuit

A. Takes the signal from the limiter/ demodulator andcleans-up any noise or left over carrier signal

B. Takes the output from the low-pass filter and amplifies itfor output

C. Takes the reproduce signal from the magnetic head andamplifies it *

D. Stabilizes the amplitude level and demodulates thesignal intelligence from the carrier signal

11. Limiter/ demodulator circuit



C. Takes the reproduce signal from the magnetic head andamplifies it

D. Stabilizes the amplitude level and demodulates thesignal intelligence from the carrier signal *

12. Low-pass filter circuit

A. Takes the signal from the limiter/ demodulator andcleans-up any noise or left over carrier signal *



D. Stabilizes the amplitude level and demodulates the

signal intelligence from the carrier signal

13. Output amplifier


B. Takes the output from the low-pass filter and amplifies itfor output *


D. Stabilizes the amplitude level and demodulates thesignal intelligence from the carrier signal

14. Which of the following generates the noise part of arecorders SNR?

A. Magnetic headsB. Magnetic tapeC. Both A and B above *D. Nearby equipment

15. The SNR can be stated in three different ways. Which ofthe following is NOT one of these ways?

A. Mean signal to RMS noise *B. Peak-to-peak signal to RMS noiseC. RMS signal to RMS noiseD. Peak signal-to-RMS noise

16. Which of the following data should be included with allSNR specifications?

A. Record level *B. Reproduce levelC. BandwidthD. Tape speed

17. What is the magnetic tape recording specification whichgives a recorders amplitude variation with frequency overa specified bandwidth?

A. Record levelB. Frequency response *C. BandwidthD. Both A and C above

18. Your LPO tells you to test the frequency response of aparticular magnetic tape recorder. You use a signalgenerator to sweep through the frequencies as you monitorthe recorders output amplitude on a VTVM. Which of thefollowing readings in output amplitude would indicate theupper and lower end of the recorders bandwidth?

A. +/- 2-dBB. +/- 3-dB *C. +/- 5-dBD. +/- 10-dB

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19. Which of the following factors can limit or degrade thefrequency response of a magnetic tape recorder?

A. The record headB. The reproduce headC. Magnetic head-to-tape contact

D. Each of the above *

20. If the frequencies of the harmonic distortion are 2, 4, and 6times the center frequency, what type of harmonicdistortion is this?

A. LinearB. SpatialC. Even-order *D. Center frequency

21. Which of the following is a cause of even-order harmonicsduring magnetic tape recording?

A. Defective magnetic tapeB. Frequency response too low

C. Permanently magnetized heads *D. Each of the above

22. If you increase a magnetic tape recorders signal biaslevel, what happens to the harmonic distortion?

A. IncreasesB. Remains the sameC. Decreases *D. Increases odd-order harmonic distortion

23. When measuring the amount of harmonic distortion in amagnetic tape recorder, what electronic test equipmentshould you use?

A. Wave analyzer *B. VTVMC. Spectrum analyzerD. All of the above

24. When measuring harmonic distortion, you set the signalgenerator to input a 12- kHz test signal. At the recordersoutput, what will be the frequency of the third-orderharmonic?

A. 33-kHzB. 18-kHzC. 38-kHzD. 36 kHz *

25. What magnetic tape recorder specification expresses the

variation of the phase shift with respect to frequency?

A. Frequency responseB. Phase response *C. Wow and FlutterD. Each of the above

26. Which of the following conditions indicates that a magnetictape recorder has a good phase response specification?

A. The SNR and frequency response are within toleranceB. The wave analyzer shows a perfect sine waveC. The recorder reproduces an undistorted square wave *D. Each of the above

27. What magnetic tape recorder specification expresses theresult of non-uniform tape motion caused by variations intape speed that produces frequency modulation of signalsrecorded onto magnetic tape?

A. Frequency responseB. Phase responseC. Flutter *D. Time-base error

28. Which of the following magnetic tape recorder transportparts can cause high frequency flutter (above 1000 Hz)?

A. Magnetic headsB. Rotating tape guidesC. Fixed tape guidesD. Both A and C above *

29. A magnetic tape recorders flutter specification is usually

expressed as a percent of peak or as a peak-to-peak valuefor what type of recorder?

A. Audio *B. InstrumentationC. VideoD. All of the above

30. The time-base error (TBE) magnetic tape recorderspecification is closely related to flutter. Which of thefollowing statements best reflects this relationship?

A. TBE is an inverse measure of the effects of flutter on thestability of recorded data

B. TBE is a direct measure of the effects of flutter on thefrequency response of recorded data

C. TBE is a direct measure of the effects of flutter on thestability of recorded data. *

D. TBE is a direct measure of the effects of flutter on thebias level of recorded data.

31. The simplest way to measure a recorders TBE is withwhat test equipment?

A. VTVMB. Sweep analyzerC. Oscilloscope *D. Ohmeter

32. There are two types of skew. What type does not show upwhen magnetic tapes are recorded and reproduced on the

same magnetic tape recorder?

A. PositiveB. DynamicC. NegativeD. Fixed *

33. Which of the following is NOT a cause of dynamic skew?

A. Gap scatter in the magnetic head stack *B. Sticking tape transport guidesC. Warped magnetic tapeD. Worn tape transport guides

34. Which of the following is NOT a format for digital magnetictape recording?

A. Serial-parallelB. Bi-phase *C. SerialD. Parallel

35. Which of the following digital magnetic tape recordingformats is normally used for instrumentation recordingwhen the input data rate is high?

A. Serial-ParallelB. Serial *C. Both A and B aboveD. Bi-phase

36. The return-to-bias digital magnetic tape recording encodingmethod uses magnetic tape that is normally in a "neutral"condition.

A. TrueB. False *

37. Which of the following digital magnetic tape encodingmethods is the most widely used?

A. RB

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B. NRZ *C. E-RZD. RZ

38. Which of the four variations of NRZ encoding works best inhigh density magnetic tape recording and offers a bit errorrate of one error per 1 million bits?

A. E-NRZ-L *B. NRZ-LC. NRZ-MD. NRZ-S

39. Digital magnetic tape recorders are used to store andretrieve which of the following types of data?

A. Computer programsB. Radar and other pulsed type signalsC. Special signals with a bandwidth of less than 500 kHzD. Each of the above *

40. Telemetry digital magnetic tape recorders are frequentlycalled wideband recorders.

A. True *B. False

41. Floppy disks are made of round plastic disks coated withmagnetic oxide particles and enclosed in a plastic jacket.

A. True *B. False

42. When discussing floppy disks, what is meant by the"density" of a floppy disk?

A. The thickness of the plastic diskB. How much the disk can store *C. The thickness of floppy disk jacket

D. The number of sectors on the disk

43. 5-1/4" double density

A. 1,200,000 bytesB. 720,000 bytesC. 360,000 bytes *D. 1,400,000 bytes

44. 5-1/4" high density

A. 1,200,000 bytes *B. 720,000 bytesC. 360,000 bytesD. 1,400,000 bytes

45. 3-1/2" double density

A. 1,200,000 bytesB. 720,000 bytes *C. 360,000 bytesD. 1,400,000 bytes

46. 3-1/2" high density

A. 1,200,000 bytesB. 720,000 bytesC. 360,000 bytesD. 1,400,000 bytes *

47. Data is stored on floppy disks in circular "tracks." Eachtrack is then broken up into arcs called "cylinders."

A. TrueB. False *

48. When a floppy disk is sectored using the soft sectoringmethod, the computer software determines the sector sizeand placement. What is this process called?

A. CenteringB. Addressing

C. Formatting *D. Rastering

49. When you handle, store, or ship floppy disks, which of thefollowing statements is NOT a precaution you should take?

A. Always store 8" and 5 1/4" floppy disks in their envelopeswhen not in use

B. Always write on a floppy disk label first, and then place iton the disk

C. Always lay floppy disks on their side when storing them *D. Always ship floppy disks in their appropriate shipping

containers

50. Which of the following items can generate magnetic fieldsthat can destroy data on a floppy disk?

A. Paper clipB. TelephoneC. PrinterD. Both 2 and 3 above *

51. How can you erase a floppy disk?

A. Record over itB. Degauss it

C. Reformat itD. Both 2 and 3 above *

52. A computer places data on a hard disk by using one ofwhat two methods?

A. Cylinder or sector *B. Cylinder or circularC. Sector or quadrantD. Sector or record

53. Using the sector method, a hard disk drive locates a placeon a hard disk with only one platter by using three locationnumbers. Which of the following is NOT one of thoselocation numbers?

A. Surface numberB. Track number *C. Cylinder numberD. Sector number

54. When you handle, store, or ship removable hard disks,which of the following statements is NOT a precaution youshould take?

A. Dont touch any exposed recording surfacesB. Keep them away from food, liquids, and cigarette smokeC. Store them in an environment that stays between 32 to

95 degrees Fahrenheit and 40 to 85% relative humidity *D. Keep dirt, dust, etc., off of the recording surface by

storing them in their case when not in use

55. How can you declassify a removable hard disk whichcontains classified information?

A. Reformat itB. Degauss itC. Both 1 and 2 aboveD. Destroy it using the procedures in OPNAVINST 5510.1 *

56. Which of the following encoding methods is NOT used forencoding digital data onto magnetic disks?

A. Sector encoding *B. Run length limitedC. Modified frequency modulationD. Frequency modulation

57. Head arm assembly

A. Holds and spins the floppy diskB. Holds the magnetic read/write heads *C. Controls the electromechanical high density partsD. Positions the heads over the disks

58. Drive electronics circuit board

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A. Holds and spins the floppy diskB. Holds the magnetic read/write headsC. Controls the electromechanical high density parts *D. Positions the heads over the disks

59. Drive motor/spindle assembly

A. Holds and spins the floppy disk *B. Holds the magnetic read/write heads

C. Controls the electromechanical high density partsD. Positions the heads over the disks

60. Actuator arm assembly

A. Holds and spins the floppy diskB. Holds the magnetic read/write headsC. Controls the electromechanical high density partsD. Positions the heads over the disks *

61. What part of a hard disk drive transport uses either a dcstepper motor or a voice coil to position the heads forwriting data to the correct track of the disk pack?

A. Drive motor/spindle assemblyB. Head arm assembly

C. Actuator arm assembly *D. Drive electronics circuit board

62. What part of a hard disk drive transport holds the fourmagnetic heads, and is attached to the transports actuatorarm assembly?

A. Cylinder assemblyB. Head arm assembly *C. Sectoring assemblyD. Drive motor/spindle assembly

63. Why do floppy disk drives require more preventivemaintenance than hard disk drives?

A. They are not sealed unitsB. Oxide coating from disks sticks to transport partsC. Both A and B above *D. The drive circuit board is less protected

64. Which of the following is a main function of the controlelectronics part of a disk drives electronics component?

A. Take incoming data from the interface electronicsB. Spin the disk at the proper speedC. Move the heads across the recording surfaceD. Both B and C above *

65. Which of the following is a function of the interfaceelectronics part of a disk drives electronics component?

A. Convert data from the host computer from serial toparallel, and vice versa, as needed

B. Receive write/read control signals from the hostcomputer

C. Receive control signals to format a disk from the hostcomputer

D. All of the above *

66. Which of the following is NOT one of the five mostcommon disk drive interfaces in use today?

A. Drive motor/spindle interface *B. Naval tactical data system interfaceC. ST-506/412 interfaceD. Enhanced small device interface

67. What type of disk drive interface is often used in the harddisk drives installed in older IBM-compatible desktopcomputers that have a maximum capacity of 125MB?

A. Drive motor/spindle interfaceB. Enhanced small device interfaceC. ST-506/412 interface *D. Integrated drive electronics

68. What type of disk drive interface uses a high-level interfacewhich requires only a logical sector number to locate thedesired data on a disk?

A. Enhanced small device interfaceB. Integrated drive electronicsC. Drive motor/spindle interfaceD. Small computer systems interface *

69. What type of disk drive interface includes all of thecontroller card electronics in the hard disk drive and offersa transfer rate of up to 1 MB?

A. Small computer systems interfaceB. Integrated drive electronics *C. Naval tactical data systemD. Enhanced small device interface

70. Which of the following is NOT a benefit of the SCSI diskdrive interface over previous interfaces?

A. Can handle disk drives of almost any sizeB. Disconnects itself from the host computers bus while i t

processes requestsC. Can transfer data up to 24 Mbits/sec *

D. Can daisy-chain up to eight units off of one controller

71. Indicates number of physical sectors that are betweenlogical sectors on a hard disk

A. Seek timeB. Latency periodC. Access timeD. Interleave factor *

72. Total time it takes a disk drive to retrieve a sector of data

A. Seek timeB. Latency periodC. Access time *

D. Interleave factor

73. Time it takes for a magnetic head to position itself over aspecific track

A. Seek time *B. Latency periodC. Access timeD. Interleave factor

74. Time it takes a specific sector of a specific track to positionitself under the magnetic head

A. Seek timeB. Latency period *C. Access time

D. Interleave factor

75. The speed at which a disk drive and a disk drive controllerworking together can transfer data to the host computer iswhat disk recording specification?

A. Seek timeB. Transfer rate *C. Access timeD. Interleave factor

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Module 23b