Chapter 2: Storage Devices and Power Supplies

1. B. A conventional HDD contains discs called platters, on which data is stored magnetically through read/write heads by way of a magnetic coating.

2. A. A conventional hard disk drive system consists of the hard disk and its often-integrated controller as well as a host adapter to gain access to the rest of the computer system. The drive interface is a common component of the controller and host adapter.

3. D. A fixed number of clusters is supported by each operating system, leading to a corresponding maximum volume size. If the maximum NTFS cluster size of 64KB is used, Windows XP can support a single-volume size of 256TB. When a cluster size of one sector, or 512 bytes (½KB), is used, the maximum volume size reduces to 2TB.

4. C. Solid-state disks (SSDs) are capable of replacing conventional HDDs, contingent upon cheaper components and higher capacities.

5. C. High-density 3½″ floppy diskettes have a formatted capacity of 1.44MB. Double-density 5¼″ floppies can be formatted to a capacity of 360KB, while double-density floppies support 720KB. The extended-density 3½″ floppy diskettes can be formatted to 2.88MB.

6. B. Blu-ray discs have a single-sided, single-layer capacity of 25GB. The best the other options achieve is no more than roughly 17GB.

7. A. Hot-swappable devices can be removed while the power to the system is still on. Warm-swappable devices need to be stopped in the operating system before being removed. The term has nothing to do with the heat level of the device.

8. C. Power supplies and AC adapters use standard wall outlets for an input of AC voltage, which they convert to the DC voltages required by the components they supply power to.

9. A, C, D, E, F. A PC’s power supply produces +3.3VDC, +5VDC, –5VDC, +12VDC, and –12VDC from a 110VAC input.

10. D. Molex power connectors have been used with larger internal devices since the original PCs hit the market. When the 3½″ floppy diskette drives were launched, they used the newer Berg connectors. Europe requires the voltage selector switch be set at the higher setting. SATA drives most often use a specific power connector that is not compatible with the Molex connector used by PATA drives. AT-based motherboards call for P8 and P9 connectors; ATX motherboards have a newer 20- or 24-pin single power connector.

11. C. Today’s hard drives, regardless of their rpm, have standard internal power connections. Each of the other options are valid concerns when installing an internal drive.

12. A. Although inefficient as an interactive medium, sequential tape-based storage continues to be developed in increasing capacities. Tape remains the best choice for frequently backing up large amounts of data for redundancy and archival purposes.

13. D. Inserting the Berg connector upside down will damage the drive the first time the motor is activated. Floppy drives require front access for floppy disk insertion. Their form factor is only 3.5″, and you can still buy them new. (See the sidebar “Do You Smell Something?” in this chapter.)

14. C. The other common spin rates are 10,000 rpm and 12,000 rpm.

15. B. Personal computers do not have permanently installed power supplies. Like other electrical and electronic components, power supplies can and do fail on a regular basis. Permanently mounting a power supply to a chassis would be a disservice to the consumer. You should consider the cumulative power needs of your installed components, and you might have to obtain adapters and splitters if you do not have enough or you have the wrong types of connectors coming from the power supply.

16. B. The red stripe on the cable indicates pin 1.

17. B. UltraDMA/66 requires a special ribbon cable with extra wires to cut down on cross-talk. It does not require Cable Select to be in use, and it does not require specific operating system support because it operates at a lower level than the OS. There is no special setting in the BIOS for UltraDMA drives.

18. B. If there is a Single setting, it should be used. Otherwise, use Master. Slave is never appropriate for a single drive. There is no such jumper setting as Boot.

19. D. Each concept applies to both HDDs and SSDs except for platter spin rates. Revolutions per minute (rpm) measurements refer to drives with moving parts. SSDs have none.

20. A. Power supplies are rated in watts. When you purchase a power supply, you should make sure the devices inside the computer do not require more wattage than the chosen power supply can offer. The voltage is fairly standard among power supplies and has nothing to do with the devices connected to the power supply. Amperage and resistance are not selling points for power supplies.