CompTIA A+ Core 1 Practice Test A

You configure a mobile device to connect to a Wi-Fi network on channel 165. Which of the following frequencies is the wireless connection using?

• 2.4 GHz

• 40 MHz

• 5 GHz

• 13.56 MHz

Answer explanation

Explanation:

The wireless connection is using the 5 GHz frequency range. 802.11n, 802.11ac, and 802.11ax use the 5 GHz range. Typical channels for Wi-Fi on 5 GHz include 36, 40, 44, 48, 149, 153, 157, 161, and 165.

Incorrect answers: 2.4 GHz is used by Wi-Fi standards such as 802.11b, 802.11g, and 802.11n. (802.11n can use both 2.4 and 5 GHz.) The standard channels for 2.4 GHz Wi-Fi (in the United States) are between 1 and 11. 40 MHz is a common channel width in Wi-Fi networks when channel bonding is incorporated. 13.56 MHz is a standard channel for near-field communication (NFC).

Which of the following CPU cooling methods is the most common?

• Heat sink

• Heat sink and fan

• Liquid cooling

• Liquid nitrogen

Answer explanation

Explanation:

The most common CPU cooling method is the heat sink and fan combination. The heat sink helps to disperse the heat away from the CPU, whereas the fan blows the heat down and through the fins; the power supply exhaust fan and possibly additional case fans help the heat escape the case. Heat sink and fan combinations are known as active cooling methods.

Incorrect answers: A heat sink used by itself provides passive cooling; it requires no power but is not enough to cool most desktop PCs. Liquid cooling is a more extreme method used in custom PCs such as gaming computers and possibly audio/video workstations and virtualization machines. It uses a coolant similar to the way an automobile does. Liquid nitrogen would be plain foolish and is not a legitimate answer.

After you replace a motherboard in a PC, the system overheats and fails to boot. Which of the following is the most likely cause?

• The GPU is not compatible with the CPU

• The new motherboard's firmware is out of date

• Thermal paste was not applied between the heat sink and the CPU

• The case fan failed

Answer explanation

Explanation:

If the motherboard was just replaced and the system overheats when booted, there’s a good chance that thermal paste was not applied to the CPU. When you install a new motherboard, the CPU must be removed from the old board and installed to the new one, or a new CPU needs to be installed. Either way, the heat sink must come off. Whenever a heat sink is connected (or reconnected) to a CPU, thermal paste (also known as thermal compound), or a thermal pad, should be applied; otherwise, CPU overheating can easily occur.

Incorrect answers: The GPU is the video card’s processor; it is not possible for the GPU to be incompatible with the CPU. It is possible for the video card to be incompatible with the expansion bus slots on the new motherboard, though. Even if the new motherboard’s firmware has not been updated, the system should not overheat. If the case fan fails, the computer should not overheat. The CPU will still have its own fan, and the power supply will still exhaust hot air.

What is the minimum number of storage drives necessary to implement RAID 5?

• Two

• Five

• Three

• Four

Answer explanation

Explanation:

Because RAID 5 uses striping with parity, a third drive (disk) is needed. You can have more than three drives as well.

Incorrect answers: Two drives are enough for plain RAID 0 striping, so two is the exact number you need for RAID 1 mirroring. RAID 6 and RAID 10 require four disks at a minimum.

You are tasked with fixing a problem with a video editing workstation. An unexpected clicking noise occurs every time the video editing program is started. The case fans have been replaced, but the noise remains. Diagnostics have also been run on the video card, and it appears to be operating normally. What action should you take first?

• Perform a system restore

• Replace the video card

• Replace the hard disk drive

• Perform a full data backup

• Scan for malware

Answer explanation

Explanation:

The first action you should take is to perform a full data backup. Clicking noises can indicate that the computer’s magnetic-based hard drive is damaged and might fail. Immediately back up the drive’s contents before taking any other action.

Incorrect answers: It is less likely, but the clicking noise can also be caused by a fan. However, the case fans have already been replaced, and it is uncommon for a video card fan to make that noise unless a cable is brushing against it (which is also unlikely). As you gain experience, you will find that fan noise and hard disk drive clicking are usually two different sounds. The damage to the hard drive could possibly be caused by malware. After backing up data, scan the drive, and, if necessary, run a System Restore. The video card should not need to be replaced because the diagnostics indicate that it is running normally. After the backup, you should strongly consider replacing the hard drive, for two reasons: (1) The drive is clicking and is probably going to fail, and (2) video editing workstations require faster hard drives. The scenario implies that the system is using a magnetic-based hard drive (also known as a hard disk drive, or HDD). A solid-state drive (SATA or M.2) would run the video editing program more efficiently and would be better in the file-rendering phase. But keep in mind that these drives have no moving parts and therefore will not present any types of clicking sounds if they are about to fail. And know this: All drives fail. It’s not a matter of if but when!

Which of the following has the fastest data throughput?

• Optical drive

• Hard disk drive

• Solid-state drive

• RAM

• USB

Answer explanation

Explanation:

RAM is much faster than the rest of the options listed. For instance, if you have PC4-25600 DDR4 RAM (aka DDR4-3200), your peak transfer rate is 25,600 megabytes per second (MB/s) (which could also be shown as 25.6 GB/s).

Incorrect answers: The rest of the devices in the incorrect answers are listed in descending order of data throughput:

Hard disk drive or solid-state drive: For example, 600 MB/s for SATA 3.0, 1969 MB/s for SATA Express, and 3500 MB/s for typical M.2 drives. M.2 is very fast but still a fraction of RAM speeds (as of the writing of this book in 2022).

USB: For example, 5 gigabits per second (Gbps) for version 3.0 and 20 Gbps for version 3.2 (which equates to 2.5 GB/s).

Optical drives, though not used often, might still be found in some systems, especially older ones. CD-ROMs typically transfer 7.5 MB/s. DVD-ROMs typically transfer 21 MB/s. Blu-ray discs can typically transfer 72 MB/s.

Which device retains data over the long term?

• CPU

• RAM

• Storage drive

• Video card

Answer explanation

Explanation:

The storage drive (or hard drive) stores data over the long term. It stores the OS and data in a nonvolatile fashion, meaning the data won’t be erased when the computer is turned off.

Incorrect answers: The CPU calculates data and sends it to RAM for temporary storage; the RAM (which is volatile) is cleared when the computer is turned off. The video card stores temporary video data within its onboard memory, but this, like RAM, is volatile and is cleared when the computer is turned off.

Which of the following is the most important piece of information needed to connect to a specific wireless network?

• Channel

• MAC address

• SSID

• Administrator password

Answer explanation

Explanation:

The service set identifier (SSID) is the most important piece of information required to connect to a wireless network; it is the name of the wireless network.

Incorrect answers: The wireless channel number isn’t necessarily needed as the wireless access point (WAP) might autonegotiate the channel. Also, MAC address filtering is not enabled by default, so the MAC address might not be needed. (In fact, the admin would enter this at the WAP, not from the client computer.) You need the administrator password only if you want to make configuration changes to the wireless access point. For example, if you want to implement MAC filtering, you have to log in to the WAP with an admin password to configure it.

You are planning to use an older PC for trade shows in several different countries. The PC only needs to work as a basic kiosk with an Internet browser. Which of the following is the most important factor for you to consider?

• Maximum wattage

• Input voltage

• Number of SATA connectors

• TDP

• Number of network connections

Answer explanation

Explanation:

The input voltage is the most important thing to consider (of the listed answers at least). Different countries have different standard input voltages. For example, the United States uses 115 volts alternating current as a standard; countries in Europe and elsewhere use 230 volts. In this case, you would want to make sure that the older PC can auto-select voltages or that it at least has a switch to change from 115 V to 230 V.

Incorrect answers: Because this PC will be used for very basic purposes, the maximum wattage, number of SATA or network connections, and thermal design power (TDP) rating should not make a difference. However, you should make sure that the PC has the correct video connections and appropriate USB connections to work as a kiosk.

An exclamation point next to a device in Device Manager indicates which of the following?

• A driver is not properly installed on the device

• The device is disabled

• The driver is not digitally signed

• The device driver needs to be upgraded

Answer explanation

Explanation:

If you see an exclamation point in Device Manager, it indicates that the device does not have a proper driver. Right-click the device in Device Manager and select Update Driver or install the driver directly from the manufacturer’s website.

Incorrect answers: If the device is disabled, it will have a down arrow next to it. If a driver was not digitally signed, the device might show up in the Unknown Devices category until it is installed properly. If a device has a working driver, upgrading it will be up to you, but you won’t necessarily be notified that the driver needs to be upgraded. This question may seem more like a 220-1102 question, but you have to be prepared for some overlap. Remember that some of the concepts of the 220-1101 and the 220-1102 exams are heavily intertwined!