PC Hardware —

Review: Questions and Answers

  1. Explain the difference between spikes, surges, and sags.

    Spikes and surges are brief, but often catastrophic, increases in the voltage source (very high voltage for a very short time). These can be caused by the power source (the local power company), but most often are caused by lightning strikes. A spike (or transient) is a very short over-voltage condition measured in nanoseconds, while a surge is measured in milliseconds. A sag is a brief decrease of voltage at the source.

  2. What are the two types of power-supply connectors to the motherboard?

    AT style with two plugs-P8 and P9, and the ATX style with a single connector.

  3. What are the two types of power-supply connectors to devices such as drives?

    The Molex, a 5-volt connector, is used for hard disk drives, and the mini 3.3-volt is used for floppy disk drives and similar devices.

  4. Name two benefits to having a UPS on a system.

    The UPS (uninterruptible power supply) buys the user some time in which to save data and properly shut down a system, in the event that a power outage has occurred. And the UPS conditions the line in the event of a spike or surge.

  5. Describe the difference between a brownout and a blackout.

    A brownout is a decrease in the voltage in the power supply. A blackout is a total power failure.

  6. When you purchase a UPS, what is the most important thing to consider?

    That the UPS offers enough time to power the computer until all data can be saved and the computer can be properly shut down.

  7. Will all surge suppressors provide protection against lightning strikes?

    No, surge suppressors offer limited protection, and it decreases with age. Also, nothing can totally protect against a nearby full-force lightning strike.

  8. What is the best defense against spikes caused by lightning?

    To protect against spikes from lightning, unplug your computer from the wall outlet.

  9. What is the most important thing to remember when connecting a P8 and P9 connector to a motherboard?

    The black (ground) wires must be installed next to each other.

  10. Explain the difference between the mini connector and the Molex connector.

    The Molex connector is the most common connector, and is used primarily for devices that need both 12-volt and 5-volt power, such as older floppy disk drives, hard disk drives, and CD-ROM drives.

    The mini connector is used primarily on 3.5-inch floppy drives. Most systems provide a mini connector.

  11. Describe the best way to make sure a new power supply matches the one you are replacing.

    Take the old one with you and match its physical size, as well as the power ratings and number of connectors, to the new one.

  12. What is the primary use of mini connectors?

    Mini connectors are primarily used for 3.5-inch floppy disk drives.

  13. A computer power supply has both 5-volt and 12-volt outputs. The 5-volt output is used to power ___________, and the 12-volt output is used to power _________.

    The 5-volt output is used to power devices that manage data only, and the 12-volt output is used to power devices that have moving parts, such as drives and fans.