12-19. A motor that moves imprecise detents when a
drive signal is applied is known as a
1. voice coil motor
2. stepper motor
3. servo motor
4. synchro
12-20. Which of the following actuators could suffer a
loss of data because of variations in temperature?
1. Voice coil
2. Stepper motor
3. Servo motor
4. Synchro
12-21. For proper positioning of the heads, which of the
following actuators requires a dedicated servo
surface or servo signal embedded in the sector
gaps?
1. Voice coil
2. Stepper motor
3. Servo motor
4. Synchro
12-22. The speed of the spindle motor in a fixed disk is
controlled by which of the following devices?
1. An optical sensor
2. A tachometer only
3. A feedback loop only
4. A tachometer and feedback loop
12-23. Timing and synchronization between a fixed disk
drive and the drive controller are accomplished
by which of the following means?
1. A clock on the controller
2. A clock on the disk drive logic board
3. Special timing signals on the disk
4. Data and flux reversal pulses
12-24. Which of the following data encoding methods is
NOT used with fixed disk drives?
1. Modified frequency modulation
2. Frequency modulation
3. Run length limited
4. Non-return-to-zero indiscrete
12-25. A fixed disk system that uses frequency
modulation to encode data will store the byte
1010 0001 as which of the following codes
(P=pulse, N=no pulse)?
1. PPPPNPNPNPPPPPNP
2. PPPNPPPNPNPNPNPP
3. NPPPNPPPPPPPPPNP
4. NPNPNPNPNPNPNPNP
12-26. Which of the following data encoding methods
groups bits together and uses a table to determine
what code is written on the disk?
1. Non-return-to-zero
2. Frequency modulation
3. Modified frequency modulation
4. Run length limited
12-27. A fixed disk system using modified frequency
modulation will encode a logic ZERO that is
preceded by a logic ONE in which of the
following ways?
1. No pulse followed by a pulse
2. A pulse followed by no pulse
3. Two no-pulse periods
4. Two pulses
12-28. Which of the following encoding methods will
increase by 50 percent the data density and
transfer rate of a fixed disk system?
1. Run length limited
2. Non-return-to-zero
3. Frequency modulation
4. Modified frequency modulation
12-29. The encoding method used to write data on a
fixed disk is determined by which of the
following means?
1. The application software installed in the
computer
2. The disk operating system (DOS) installed in
the computer
3. The disk controller
4. The manufacturer of the disk drive
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