220-1101 CompTIA A+ Certification Exam: Core 1 Free Practice Exam Questions (2025 Updated)

An MX (Mail Exchange) record specifies the mail server responsible for receiving email for a domain.

Why Not A (CNAME): CNAME is used for domain aliasing, not for email delivery.

Why Not B (SRV): SRV records are used to locate specific services, not mail servers.

Why Not D (SOA): SOA records provide domain information but do not handle email.

CompTIA A+ Exam Reference: Core 1 (220-1101), Section 2.6, DNS record types​.

In laser printing, the fuser unit is responsible for bonding the toner to the paper using heat and pressure. If the toner is not sticking to the paper, resulting in illegible documents despite trying different brands of paper, it indicates a problem with the fuser unit. It might not be reaching the necessary temperature to melt the toner properly, necessitating its replacement to ensure proper printouts.

For setting up a private network, the IP address range should be one that is reserved for private use. The range 172.16.0.0 to 172.31.255.255 falls within the set of IP addresses designated for private networks according to RFC 1918. This range is not routable on the public internet, making it ideal for a private network setup on a retail router.

If paper gets stuck at the last stage of printing, the rollers responsible for moving the paper through the printer are likely worn out or dirty.

Why Not B (Tray assembly): The tray assembly manages paper loading, not feeding during the print process.

Why Not C (Toner): Toner is unrelated to paper jams.

Why Not D (Printhead): Printheads manage ink/toner distribution, not paper movement.

CompTIA A+ Exam Reference: Core 2 (220-1102), Section 4.6, printer troubleshooting​.

If a smartphone repeatedly loses connection to a home Wi-Fi network and the common troubleshooting steps like restarting the device, rebooting the router, and resetting the Wi-Fi settings have not resolved the issue, updating the smartphone's operating system (OS) could be the next logical step. OS updates often include fixes for known bugs and improvements in connectivity and compatibility with network hardware, which could resolve persistent connection issues.

Comprehensive and Detailed Step-by-Step Explanation:

LC Connector (Lucent Connector):

LC is a type of fiber optic connector commonly used in optical networking cables. It is small, compact, and widely used for high-speed data transfer over fiber optic networks.

LC connectors are specifically designed for fiber optic cables, making them the correct answer.

Incorrect Options:

A. RJ45: RJ45 connectors are used for Ethernet cables (twisted-pair copper cabling) and are not compatible with optical networking cables.

C. USB-C: USB-C is a connector type used for general-purpose data transfer, charging, and video output, not for optical networking.

D. Lightning: Lightning connectors are proprietary to Apple devices and are not used in optical networking.

Key Takeaway:

The LC connector is specifically designed for fiber optic cables, making it the correct answer for optical networking.

After resolving the immediate issue (reactivating server credentials), verifying system functionality ensures the solution works as intended and the user can now access the shared drive. This step is a part of the CompTIA troubleshooting methodology:

Identify the problem.

Establish a theory of probable cause.

Test the theory to determine the cause.

Establish a plan of action.

Implement the solution.

Verify full system functionality.

Document findings, actions, and outcomes.

Why Not B (Document the findings): Documentation comes after verifying the system works.

Why Not A (Escalate the issue): Escalation is unnecessary since the problem was resolved.

Why Not C (Perform backups): Performing backups is unrelated to verifying credential functionality.

CompTIA A+ Exam Reference: Core 2 (220-1102), Section 3.1, troubleshooting methodology​​.

The most important step the technician should take before proceeding is A. Verify the device is fully charged and connected to a power supply.

Firmware is a type of software that controls the basic functions and operations of a device, such as a router, printer, or scanner. Firmware can be updated to fix bugs, improve performance, or add new features to the device. However, updating firmware can also be risky, as it may cause the device to malfunction or become unusable if the update process is interrupted or corrupted.

One of the main causes of firmware update failure is power loss, which can occur if the device runs out of battery or is disconnected from the power source during the update. Power loss can damage the firmware and prevent the device from booting up or functioning properly. Therefore, it is essential to verify that the device is fully charged and connected to a power supply before updating the firmware. This can ensure that the device has enough power to complete the update process and avoid any interruptions or errors.

The other options are not as important as verifying the power status of the device. Ensuring the device has adequate storage space for the update is a good practice, but it is not likely to cause a major problem if the device does not have enough space. The update process will either fail to start or prompt the user to free up some space before proceeding. Verifying administrative access on the device is also a good practice, but it is not necessary for updating firmware. Administrative access is required for installing or uninstalling software applications, but not for updating firmware. Firmware updates are usually provided by the device manufacturer or vendor and do not require user authentication. Exporting the user settings so they can be imported after the upgrade is a precautionary measure, but it is not mandatory for updating firmware. Firmware updates do not usually affect the user settings or data on the device, unless they are incompatible or corrupted. Exporting the user settings can help restore them in case of any problems, but it does not prevent them from occurring.

The Syslog server collects logs and system messages from devices on a network. It’s a standard protocol used to store log messages from network hardware like routers, switches, and servers for diagnostics and auditing.

Option A (DNS): Translates domain names into IP addresses, not used for logging.

Option B (Mail): Manages email communication.

Option C (Print): Manages print jobs and printer sharing.

CompTIA A+ Core 1 Exam Objective Reference:

Objective 2.4: Compare and contrast common networking hardware.

Step by Step Detailed Comprehensive Explanation with All CompTIA References:

Analysis of the Problem:

Multiple peripherals are non-functional, and the USB-C hub is a common point of failure.

Option Evaluation:

A. Verify the AC adapter voltage: Power issue could cause shutdowns, not device failure. Incorrect.

B. Repair the operating system: Not relevant since alternate devices are tested. Incorrect.

C. Replace the user's USB-C hub: Faulty hubs cause multiple peripheral failures. Correct.

D. Reinstall the drivers for affected devices: Driver issues wouldn’t affect all peripherals. Incorrect.

E. Make sure the printer is not drawing too much power: This is uncommon for peripherals via a hub. Incorrect.

Two-factor authentication (2FA) is a method of verifying a user’s identity by requiring two pieces of evidence: something the user knows (such as a password) and something the user has (such as a device). A mobile authenticator application is a software program that runs on a smartphone or tablet and generates a one-time code or token that the user can enter along with their password to access a system. This adds an extra layer of security to prevent unauthorized access.

References

•The Official CompTIA A+ Core 1 Student Guide (Exam 220-1101), page 13-14

•CompTIA A+ Certification Exam Core 1 Objectives, page 9, objective 2.5

•What is Two-Factor Authentication?

The best way to start troubleshooting a non-specific error after a scheduled computer restart is to review the system event log. The system event log is a record of significant events that occur on the computer, such as errors, warnings, or information messages. The system event log can help identify the cause of the error and provide possible solutions. The answer is C.

To learn more about troubleshooting methods and tools, you can refer to the CompTIA A+ Certification Exam Core 1 Objectives1 or the CompTIA A+ Core 1 (220-1101) Certification Study Guide2. These resources cover the topics that are tested on the CompTIA A+ Core 1 exam, which is one of the two exams required to earn the CompTIA A+ certification. The CompTIA A+ certification validates your skills and knowledge as an entry-level IT professional.

A DNS record is a data entry in a DNS server that maps a domain name to a specific value, such as an IP address, a mail server, a name server, or a text string. There are different types of DNS records for different purposes, and each type has a specific format and syntax12.

The A record, also known as the address record, is the most common type of DNS record, and it is used to look up the IP address assigned to a domain name. The A record maps a domain name to an IPv4 address, which is a 32-bit numerical value that identifies a device on the internet. For example, the A record for www.google.com is 172.217.14.20612.

The other options are not correct because they are not used to look up the IP address assigned to a domain name. The MX record, also known as the mail exchange record, is used to specify the mail servers that handle the email for a domain name. The MX record maps a domain name to a priority value and a host name of a mail server. For example, the MX record for gmail.com is 10 alt1.gmail-smtp-in.l.google.com12.

The NS record, also known as the name server record, is used to delegate a domain name to a set of authoritative name servers. The NS record maps a domain name to a host name of a name server that can provide authoritative answers for the domain name and its subdomains. For example, the NS record for example.com is ns1.example.com12.

The SPF record, also known as the sender policy framework record, is used to prevent email spoofing and spamming by validating the sender’s identity. The SPF record maps a domain name to a text string that specifies the authorized mail servers and IP addresses that can send email on behalf of the domain name. For example, the SPF record for microsoft.com is v=spf1 include:spf.protection.outlook.com -all12.

Lightning is a proprietary connection type that is used by Apple devices, such as iPhones, iPads, and iPods, to transfer data, charge, and connect to accessories. Lightning cables have a reversible 8-pin connector that can be plugged into a USB port on a workstation or a power adapter. USB-C, serial, and NFC are not compatible with Apple phones.

A virtual sandbox is an isolated environment that mimics the characteristics of a real system, but does not affect or interact with it1. A virtual sandbox can be used to run potentially unsafe or malicious code and observe its behavior without risking harm to the host machine or network2. This is useful for cybersecurity researchers who want to test and analyze malware samples, such as viruses, worms, ransomware, etc., and understand how they work and how to prevent or mitigate them3.

The correct answer is D. Cat 6a.

Cat 6a (augmented) is a type of twisted pair cable that supports 10GBASE-T data transmission speed. 10GBASE-T is an Ethernet standard that can deliver 10 gigabits per second (Gbps) over copper cables. Cat 6a can support this speed up to a distance of 100 meters, which is the same as Cat 5e and Cat 6 for lower speeds. Cat 6a has better shielding and crosstalk prevention than Cat 6, which makes it more suitable for high-frequency signals.

Cat 3, Cat 5, and Cat 5e are not capable of supporting 10GBASE-T data transmission speed. Cat 3 can only support up to 10 Mbps, Cat 5 can only support up to 100 Mbps, and Cat 5e can only support up to 1 Gbps. These cables have lower bandwidth, higher attenuation, and more interference than Cat 6a.

RAID 10 is a combination of RAID 1 and RAID 0, which provides both performance and redundancy. RAID 1 mirrors data across two or more disks, while RAID 0 stripes data across two or more disks. RAID 10 combines these two methods to create a mirrored stripe set, which can tolerate multiple disk failures as long as they are not in the same mirror. RAID 10 requires at least four disks and offers better performance than RAID 5, which uses parity to provide redundancy. References: https://www.comptia.org/blog/what-is-raid-0-1-5-6-10

A network jack faceplate is a device that covers and protects the network jack or outlet on a wall or a floor. A network jack or outlet is a physical interface that allows a network cable, such as an Ethernet cable, to be plugged into a network device, such as a computer or a printer. A network jack faceplate usually has one or more ports that correspond to different types of network cables, such as RJ-45, RJ-11, or coaxial.

A label on a network jack faceplate should refer to the patch panel port that the network jack or outlet is connected to. A patch panel is a device that connects multiple network cables in an organized and convenient way. A patch panel has a number of ports that correspond to different cables, such as Ethernet, coaxial, or fiber-optic cables. A patch panel can help simplify the wiring and management of a network, as well as provide flexibility and scalability for adding or changing network devices.

By labeling the network jack faceplate with the patch panel port, the network technician can easily identify and trace the cable that is connected to the network jack or outlet. This can help to troubleshoot and resolve network issues, such as connectivity, performance, or configuration problems. It can also help to avoid confusion or errors when installing or modifying network cables.

The correct answer is D. VPN.

A VPN (Virtual Private Network) is a service that allows a remote user to access network resources securely over the internet. A VPN creates an encrypted tunnel between the user’s device and the VPN server, which acts as a gateway to the network. The user can then access the network resources as if they were directly connected to the network, without exposing their traffic to eavesdropping, interception, or censorship.

A VPN can provide remote users with access to various services on a company network, such as file and print services, client/server applications, and remote network administration1. A VPN can also protect the user’s privacy and identity online by masking their IP address and location.

A firewall is a network device that performs stateful packet inspection, which means it analyzes incoming and outgoing network traffic based on predefined rules and filters, and allows or blocks packets based on their source, destination, protocol, port, or content. A firewall can enhance security by preventing unauthorized access, blocking malicious traffic, enforcing policies, and logging events. A firewall can be hardware-based or software-based, or a combination of both. Reference: https://www.comptia.org/training/books/a-core-1-220-1101-study-guide (page 78)

A clicking hard drive is usually a sign of a mechanical failure, where the read/write heads are not functioning properly or the platters are scratched or broken. This can be caused by physical shock, such as dropping the laptop while it was turned on. A damaged hard drive may not be able to boot up the operating system or access the data stored on it. This is a serious problem that requires data recovery and hard drive replacement.

References

Identifying Hard Drive Sounds and Determining What They Mean

Hard Drive Clicking? See How to Fix Click Hard Drive On Your Own

Chapter 3: Hardware

The best way to protect the data of a virtual machine in the event of hardware failure is to use a cloud-based backup solution. A cloud-based backup solution is a service that copies and stores the data of a virtual machine to a remote server or storage device over the internet. A cloud-based backup solution can offer several benefits, such as:

High availability and reliability: A cloud-based backup solution can ensure that the data of a virtual machine is always accessible and recoverable, even if the hardware that hosts the virtual machine fails or is damaged. A cloud-based backup solution can also provide redundancy and fault tolerance, by replicating the data across multiple locations or regions.

Scalability and flexibility: A cloud-based backup solution can adapt to the changing needs and demands of the virtual machine, by allowing the user to adjust the backup frequency, retention period, and storage capacity. A cloud-based backup solution can also support different types of backup, such as full, incremental, or differential, depending on the user’s preferences and requirements.

Cost-effectiveness and simplicity: A cloud-based backup solution can reduce the cost and complexity of maintaining a backup infrastructure, by eliminating the need to purchase, install, or manage hardware, software, or licenses. A cloud-based backup solution can also automate and streamline the backup process, by providing easy-to-use tools and interfaces, such as web portals, APIs, or scripts.

Other options, such as redundant hardware, UPS, or RAID, may improve the performance or resilience of the hardware that hosts the virtual machine, but they do not provide a complete protection for the data of the virtual machine in the event of hardware failure. Redundant hardware is a technique that uses multiple components or devices to perform the same function, so that if one fails, another can take over. UPS (uninterruptible power supply) is a device that provides backup power to a system in case of a power outage or surge. RAID (redundant array of independent disks) is a technology that combines multiple disks into a logical unit, to improve the speed, capacity, or reliability of the storage. However, these options may not prevent data loss or corruption due to other causes, such as human error, malware, or natural disasters. Therefore, a cloud-based backup solution is the best way to protect the data of a virtual machine in the event of hardware failure.

A router is a network device that connects multiple networks together and directs data packets to their intended destinations. This includes directing packets to networks outside of the local area network (LAN). Routers use routing tables to determine the best path for data packets to travel.

Hubs and switches operate within a single LAN and are not capable of routing packets to external networks.

Bridges can connect two LANs together, but they do not have the intelligence to route packets to external networks.

Therefore, only routers are capable of directing packets to networks outside of the LAN.

According to the CompTIA A+ Core 1 (220-1101) Certification Study Guide1, a network crimper and a cable stripper are the tools that a technician should use to resolve this issue. A network crimper is used to attach a new RJ-45 connector to the end of the cable, and a cable stripper is used to remove the outer insulation of the cable and expose the twisted pairs of wires. A toner probe, a punchdown tool, a multimeter, and a loopback plug are not needed for this task.

Here are some web resources that explain how to repair an Ethernet cable:

Ethernet Cable Repair - iFixit: This guide provides step-by-step instructions and pictures on how to fix a broken Ethernet cable.

How to Repair a Cut Cat5e Ethernet Cable - wikiHow: This article shows how to solder the wires of a cut Ethernet cable and use shrink tube to cover the joints.

Amazon.com: Ethernet Cable Repair Kit: This page lists some products that can be used to repair an Ethernet cable, such as crimping tools, connectors, testers, and strippers.

One of the possible causes of the error message “No input source” is that the LCD projector is not receiving any signal from the connected device, such as a laptop1. This could be due to a loose or faulty cable or connector, or an incorrect input source selected on the projector2. Therefore, the first troubleshooting step that the technician should take is to check the physical cabling and make sure it is properly connected and secured12.

HDD fragmentation is a condition where the data on a hard disk drive (HDD) is not stored in contiguous clusters, but scattered across different physical locations on the disk. This happens when files are created, modified, or deleted over time, leaving gaps and fragments of data on the disk. HDD fragmentation can affect the performance of the PC, especially when accessing large files that require more disk operations to read or write12.

According to some web search results123, some signs and symptoms of a heavily fragmented HDD are:

•Longer load times for files and programs

•Graphics-heavy apps and games take too long to load new windows or process new environments

•Reduced disk space and efficiency

•Increased disk noise and temperature

•Accelerated disk wear and failure

To fix this issue, the user can use a tool called Disk Defragmenter, which is built-in in Windows. Disk Defragmenter rearranges the fragmented data on the HDD so that it is stored in contiguous clusters, improving the disk performance and reliability1. Disk Defragmenter can run on a schedule or manually by following these steps1:

•Open Disk Defragmenter by clicking the Start button. In the search box, type Disk Defragmenter, and then, in the list of results, click Disk Defragmenter.

•Under Current status, select the disk you want to defragment.

•To determine if the disk needs to be defragmented or not, click Analyze disk. If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.

•Once Windows is finished analyzing the disk, you can check the percentage of fragmentation on the disk in the Last Run column. If the number is above 10%, you should defragment the disk.

•Click Defragment disk. If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.

•Disk Defragmenter might take from several minutes to a few hours to finish, depending on the size and degree of fragmentation of your hard disk. You can still use your computer during the defragmentation process.

The most likely cause of the wireless network connectivity issues is A. External interference.

External interference is any signal or noise that disrupts or degrades the quality of a wireless network. External interference can come from various sources, such as other wireless networks, cordless phones, microwaves, Bluetooth devices, or electrical appliances. External interference can affect the wireless network performance, reliability, and security, by causing issues such as signal loss, packet drops, latency, or interference.

In this scenario, a company in a large building uses a wireless network for its workstations. After a new company moves into the building on the floor below, the old company’s wireless network begins experiencing connectivity issues. This could indicate that the new company’s wireless network is using the same or overlapping frequency channel as the old company’s wireless network, and creating external interference. Wireless networks use radio frequency channels to transmit and receive data, and each channel has a certain bandwidth and range. If two or more wireless networks use the same or overlapping channel, they may interfere with each other and cause congestion or collision.

To resolve this issue, the old company’s network technician should change the wireless network channel to a different one that is less crowded or more compatible with the wireless network standard. The technician should also check the wireless network settings and features, such as SSID (Service Set Identifier), encryption, authentication, or power level, and adjust them if necessary. The technician should also scan the wireless environment and identify the sources and levels of external interference, and try to avoid or minimize them if possible.

For more information about external interference and how to prevent or reduce it, you can refer to the following web search results: [What Is Wireless Interference?], [How to Find the Best WiFi Channel for Your Router], [How to Reduce Wireless Interference].

The answer is C. Test the theory to determine the cause.

According to the CompTIA A+ troubleshooting methodology, the steps to troubleshoot any problem are:

Identify the problem and act

Establish a theory of probable cause

Test the theory to determine the cause

Establish a plan of action to resolve the problem and implement the solution

Verify system functionality and implement preventive measures

Document key findings, actions, and outcomes

In this scenario, the technician has already identified the problem (trouble accessing files on the network) and established a theory of probable cause (a failed NIC). The next step is to test the theory to determine the cause, which involves verifying whether the NIC is working properly or not.

Some possible ways to test the theory are:

Check the physical connection and status of the NIC port and cable12

Check the link state and speed of the NIC using ethtool or ip commands2

Check the configuration and state of the NIC using nmcli, teamdctl, or teamnl commands2

Check the driver and firmware of the NIC using lspci, modinfo, or dmesg commands2

Check the logs for any errors or warnings related to the NIC using journalctl or grep commands2

Uninstall and reinstall the NIC driver using Device Manager or modprobe commands13

Replace the NIC or cable with a known good one and test again13

If any of these tests confirm that the NIC is faulty, then the technician can proceed with the next step of establishing a plan of action to resolve the problem and implement the solution. If none of these tests reveal any issues with the NIC, then the technician can eliminate it as a probable cause and look for other possible causes. Therefore, option C is the correct answer.

Memory modules are physical components that store data and instructions for the computer to access and process. Memory modules have different specifications and features, such as type, speed, capacity, voltage, and form factor. These specifications and features must be compatible with the motherboard and the processor of the computer, otherwise the memory modules may not work properly or cause errors.

In this scenario, the technician is working to replace a single DDR3 RAM module on a laptop that has two occupied slots. DDR3 stands for Double Data Rate 3, and it is a type of memory technology that offers faster performance and lower power consumption than its predecessors. DDR3 RAM modules have different variants, such as DDR3L, DDR3U, or DDR3R, which have different voltage requirements. For example, DDR3L operates at 1.35V, DDR3U operates at 1.25V, and DDR3R operates at 1.5V.

When the technician tries to turn on the laptop, the computer starts beeping and does not pass POST. POST stands for Power-On Self-Test, and it is a process that checks the hardware components and functionality of the computer before loading the operating system. If POST detects an error or a failure, it may produce a series of beeps or codes to indicate the problem. The number and pattern of beeps or codes may vary depending on the manufacturer or model of the computer.

The technician double-checks the newly installed RAM and notices a motherboard message indicating low voltage. This means that the motherboard is not receiving enough power from the memory module to operate normally. This could indicate that the memory module is not compatible with the motherboard or the processor, or that it is defective or damaged. The most likely cause of this issue is that the technician installed an unsupported memory module that has a lower voltage than what the motherboard or the processor requires.

To resolve this issue, the technician should remove the newly installed RAM module and replace it with a compatible one that has the same voltage as the existing ones. The technician should also check the specifications and features of the motherboard and the processor to ensure that they support the type, speed, capacity, and form factor of the memory modules. The technician should also follow proper safety precautions when handling memory modules, such as wearing an anti-static wrist strap, avoiding physical damage or static discharge, and aligning the notches correctly.

The correct answer is B. Gather additional details.

According to the CompTIA troubleshooting process for the A+ certification exams1, the technician should gather additional details after testing a theory that is incorrect. This step helps to identify the problem more accurately and establish a new theory of probable cause. The other options are not appropriate for this stage of the troubleshooting process. Documenting the findings, escalating the problem, and identifying user changes are steps that should be done later in the process, after determining the cause and implementing a solution1.

An overheating processor is the most likely cause of a computer that has a loud system fan and randomly freezes and reboots. A processor generates heat when it performs calculations, and if the heat is not dissipated properly, it can damage the processor or cause it to malfunction. A loud system fan indicates that the fan is working harder to cool down the processor, but it may not be enough to prevent overheating. A computer that freezes and reboots randomly is a common symptom of an overheating processor, as the system tries to protect itself from further damage by shutting down or restarting.

The other options are not as likely to cause these issues. A failing hard drive may cause data loss, corruption, or slow performance, but it does not affect the system fan or the processor temperature. A defective power supply may cause the computer to shut down unexpectedly, but it does not cause the system fan to be loud or the processor to overheat. Incompatible hardware may cause the computer to fail to boot, display errors, or crash, but it does not cause the system fan to be loud or the processor to overheat.

To troubleshoot and resolve an overheating processor issue, the technician should check and clean the air vents, provide proper ventilation, apply thermal paste, replace the fan or the heat sink, or upgrade the processor if necessary. The technician should also update the BIOS and the device drivers, adjust the power settings, and monitor the system temperature using diagnostic tools.

A wireless adapter is a device that allows a laptop to connect to a wireless network, such as a home Wi-Fi router. A wireless adapter can be either internal or external, and it can be enabled or disabled by the user or the operating system. If the wireless adapter is disabled, the laptop will not be able to access the internet when it is not connected to a wired network, such as the office dock.

The technician should do the following steps to enable the wireless adapter:

Check the physical switch or button on the laptop that controls the wireless adapter. Some laptops have a switch or button on the side, front, or keyboard that can turn on or off the wireless adapter. Make sure the switch or button is in the on position.

Check the software settings for the wireless adapter. In Windows 10, you can do this by clicking on the network icon in the system tray, and then clicking on the Wi-Fi icon. Make sure the Wi-Fi is turned on. You can also go to Settings > Network & Internet > Wi-Fi and make sure the Wi-Fi is turned on.

Check the device manager for the wireless adapter. In Windows 10, you can do this by right-clicking on the Start menu and selecting Device Manager. Expand the Network adapters category and look for your wireless adapter. Make sure it is enabled and has no errors. You can right-click on it and select Enable device or Update driver if needed.

If none of these steps work, there may be a hardware or software problem with the wireless adapter that requires further troubleshooting or replacement.

The internal antennas are the components that allow the laptop to receive and transmit wireless signals. If the internal antennas are not connected properly, the laptop may have a weak or no Wi-Fi signal. The technician should verify that the internal antennas are connected to the wireless card and routed correctly inside the laptop case. The internal antennas may have been disconnected or damaged during the screen replacement. The device having the latest OS updates, the wireless device drivers being the latest version, airplane mode being disabled, and the battery being charging are not related to the issue, as they do not affect the physical connection of the internal antennas. References: https://www.comptia.org/blog/what-is-a-laptop-antenna

A redundant power supply is a type of power supply that consists of two or more independent units that can provide power to the same device or system. A redundant power supply can increase the reliability and availability of the device or system, because if one unit fails, the other unit can take over and continue to provide power without interruption. A redundant power supply is often used in servers that require continuous availability, such as web servers, database servers, or file servers.

A digitizer is a device that converts analog signals, such as touch or pressure, into digital signals that can be processed by a computer. A digitizer is usually embedded in the screen of a smartphone or tablet, and it works with a compatible stylus to enable drawing and writing on the screen1.

There are different types of digitizers and styluses, such as capacitive, resistive, active, and passive. Capacitive digitizers and styluses work by detecting changes in the electric field on the screen when the stylus touches it. Resistive digitizers and styluses work by detecting changes in the resistance on the screen when the stylus presses it. Active digitizers and styluses work by using an electromagnetic field to communicate between the stylus and the screen. Passive digitizers and styluses work by using a special material on the tip of the stylus that mimics the human finger2.

Not all digitizers and styluses are compatible with each other. For example, an active stylus will not work with a capacitive or resistive digitizer, and vice versa. A passive stylus will work with any digitizer, but it will not have any advanced features, such as pressure sensitivity or tilt control2.

The correct answer is B. 802.11ax.

802.11ax, also known as Wi-Fi 6 or Wi-Fi 6E, is the latest wireless standard that can operate in the 6GHz frequency range. This standard was approved by the IEEE in February 2021 and offers higher throughput, lower latency, and improved efficiency compared to previous standards1

The 6GHz frequency range spans from 5.925 GHz to 7.125 GHz and provides 1200 MHz of additional spectrum for Wi-Fi devices. This means that Wi-Fi 6E can support more channels, wider bandwidths, and less interference than the existing 2.4 GHz and 5 GHz bands. Wi-Fi 6E can access up to 59 20-MHz channels, 29 40-MHz channels, 14 80-MHz channels, or 7 160-MHz channels in the 6GHz band1

802.11ac, also known as Wi-Fi 5, is the previous wireless standard that can only operate in the 5GHz frequency range. It was approved by the IEEE in December 2013 and offers faster speeds and better performance than older standards. However, it cannot use the new spectrum in the 6GHz band and has limited channel availability and capacity in the crowded 5GHz band2

802.11g and 802.11n are older wireless standards that can only operate in the 2.4GHz frequency range. They were approved by the IEEE in June 2003 and October 2009, respectively, and offer lower speeds and performance than newer standards. They also suffer from more interference and congestion in the saturated 2.4GHz band, which is shared by many other devices and technologies32

A managed switch is a network device that can be configured to create VLANs (Virtual Local Area Networks), which are logical segments of a network that isolate traffic based on criteria such as function, security, or quality of service. A VLAN can be used to isolate voice traffic on the network, which can improve the performance and security of voice over IP (VoIP) applications. A network tap, a hub, and a DSL filter are not capable of creating VLANs.