CompTIA A+ Sample Questions and Explanations

Look at each row (stripe). Each one has data blocks spread across the disks plus exactly one parity block, and the parity block moves to a different disk in each row. Striping with distributed parity is RAID 5. If one disk fails, the missing data can be rebuilt from the other blocks and the parity.

Wrong choices

• RAID 0: RAID 0 stripes data with no parity at all. The figure has parity blocks.
• RAID 6: RAID 6 keeps two parity blocks in every stripe. The figure has only one parity block per row.
• RAID 10: RAID 10 keeps identical copies of data on mirrored pairs. The figure has no duplicate blocks, only one parity block per row.

ipconfig lists the network settings of each adapter, including IP address, subnet mask, and default gateway. ipconfig /all adds more detail, such as DNS servers and the MAC address.

Wrong choices

• nslookup: nslookup asks a DNS server about a name. It does not show the PC's IP settings.
• tracert: tracert shows the path to a remote host, not the PC's own IP settings.
• ping: ping tests whether another device can be reached. It does not list the PC's own settings.

RAID 1 (mirroring) writes the same data to two drives at the same time. If one drive fails, the other still has everything. It needs only two drives, and the usable space equals one drive.

Wrong choices

• RAID 5: RAID 5 also protects data, but it needs at least three drives.
• RAID 0: RAID 0 splits data across drives for speed and keeps no copy. If one drive fails, all data is lost.
• RAID 10: RAID 10 needs at least four drives.

Event Viewer keeps logs of what happens in Windows, such as application errors, system warnings, and security events like sign-ins. It is a good place to look when you need to know what went wrong and when.

Wrong choices

• Disk Management: Disk Management manages drives and partitions, not logs.
• Task Scheduler: Task Scheduler runs tasks at set times. It does not show the system's error logs.
• Device Manager: Device Manager lists hardware and drivers. It does not keep the system's event logs.

The CompTIA troubleshooting steps start with identifying the problem: talk to the user, find out what changed, try to repeat the problem, and back up data before making changes. Only then does the technician form and test a theory.

Wrong choices

• Test the theory to determine the cause: Testing comes after a theory has been formed.
• Document findings, actions, and outcomes: Documenting is the last step, after the problem is fixed and verified.
• Establish a theory of probable cause: A theory comes second, after the technician has gathered information about the problem.

Phishing uses fake emails or websites that look real to trick people into giving up passwords or other information. Banks do not ask you to confirm your password through an email link. When in doubt, go to the site by typing its address yourself.

Wrong choices

• Shoulder surfing: Shoulder surfing is watching someone's screen or keyboard to steal information.
• Vishing: Vishing is the same kind of trick done over a voice phone call, not email.
• Tailgating: Tailgating is following someone through a secure door, not sending an email.

A small coin battery on the motherboard keeps the firmware clock and settings when the PC has no power. When that battery dies, the clock and settings reset every time the PC is unplugged. Replacing the battery fixes it.

Wrong choices

• The hard drive is failing: A failing drive causes slow access, errors, or noises. It does not reset the clock or firmware settings.
• The power supply is failing: A failing power supply causes shutdowns or no power, not lost settings after the PC is unplugged.
• The time zone is set wrong in Windows: A wrong time zone gives a time that is off by a set amount every day. It does not reset the firmware settings.

Ransomware encrypts a victim's files and demands money for the key. The best protection is good backups kept separate from the network, along with updates and careful email habits.

Wrong choices

• Adware: Adware shows unwanted ads. It does not encrypt files.
• Keylogger: A keylogger records keystrokes. It does not lock files for ransom.
• Spyware: Spyware secretly watches and reports what a user does. It does not lock files and demand payment.

Bluetooth devices only work together after they are paired. The headset was paired with the old phone, not the new one. Putting the headset in pairing (discoverable) mode and selecting it in the new phone's Bluetooth settings links the two.

Wrong choices

• Turn on NFC and hold the headset against a card reader: NFC is used for touch-range actions like payments, and a card reader plays no part in connecting a headset.
• Reset the phone to factory settings: A factory reset erases the phone and is far too drastic as a first step. The new phone has simply never been paired with the headset.
• Turn on the phone's mobile hotspot: A hotspot shares cellular data over Wi-Fi. It has nothing to do with connecting a Bluetooth headset.

Electrostatic discharge (ESD) is a sudden spark of static electricity that can damage computer parts, even when you cannot feel it. An ESD wrist strap connected to ground keeps you at the same charge as the computer so no spark jumps to the parts.

Wrong choices

• A magnetic screwdriver: Magnets do not protect against static electricity.
• Rubber-soled shoes on a carpet: Walking on carpet can build up static, and rubber soles do not drain it away.
• A wool sweater: Wool can build up static charge, which makes the problem worse.