Free CompTIA A+ Core 1 Sample Questions

Correct answer: C — USB tethering

• A. Wi-Fi Direct creates a direct wireless connection between devices without requiring a wireless access point; however, it is a wireless technology and does not involve a physical cable.
• B. Bluetooth pairing allows devices to connect wirelessly over short distances. While it can be used for tethering (Bluetooth tethering), it does not satisfy the requirement of using a physical cable.
• C. USB tethering is the correct technology for sharing a mobile device's cellular data connection with a laptop via a physical USB cable. This provides a stable, wired data link.
• D. NFC (Near Field Communication) is used for extremely short-range wireless communication, such as contactless payments and quick device pairing. It is not used for internet sharing or physical cable connections.

Correct answers: A, C — Both devices must have Bluetooth enabled.; The headset must be in discoverable mode.

• A. Correct. Bluetooth must be enabled on both devices to allow them to detect and communicate with one another using the Bluetooth protocol. This is the fundamental starting point for any Bluetooth connection.
• B. Incorrect. Bluetooth and Wi-Fi are distinct wireless technologies. Bluetooth operates as a Personal Area Network (PAN) and does not require a Wi-Fi network to function or pair devices.
• C. Correct. For a device like a headset to be detected by a smartphone during a scan, it must be placed in discoverable (or pairing) mode. This broadcasts the device's availability to other nearby Bluetooth devices.
• D. Incorrect. Bluetooth communication is local between the two devices and is completely independent of cellular networks, mobile data, or SIM card status.
• E. Incorrect. While devices must have sufficient power to operate, they do not need to be physically plugged into an outlet. Bluetooth is designed for mobile, battery-powered operation.

Correct answers: A, C — Plastic spudger; Heat gun

• A. Correct. A plastic spudger is a non-conductive, anti-static tool used to safely separate clips and pry open delicate electronic devices. Because it is made of plastic, it is less likely to scratch the casing or cause an electrical short compared to metal tools.
• B. Incorrect. A power drill is a destructive tool in this context. It is far too aggressive for opening a tablet and would likely result in cracked housings, debris inside the device, and permanent damage to internal components.
• C. Correct. Sealed tablets often use strong industrial adhesive rather than screws to hold the screen to the chassis. A heat gun is used to soften this adhesive, making it possible to safely separate the components without applying excessive physical force that could crack the screen.
• D. Incorrect. Wire strippers are specialized tools for removing the insulation from electrical wires. They do not provide the flat surface area or leverage required to open a device casing.
• E. Incorrect. Metal pry bars are too rigid and sharp for delicate mobile repairs. Using metal against a glass screen or plastic/aluminum housing can easily lead to cracking the glass, bending the frame, or causing electrical shorts.

Correct answer: A — Wi-Fi and Bluetooth

• A. Internal mobile device antennas are specifically designed for wireless radio communications. Wi-Fi and Bluetooth are the most common short-range wireless signals handled by these assemblies in devices such as smartphones, tablets, and laptops.
• B. Ethernet and Token Ring are wired networking standards. Because they require physical cabling for signal transmission, they are not routed through the internal wireless antenna assembly.
• C. HDMI and DisplayPort are interface standards for high-definition video and audio that utilize physical cables and connectors. They are not transmitted via radio waves and therefore do not use internal antennas.
• D. USB and Thunderbolt are high-speed wired data and power delivery interfaces. These rely on physical ports and cables rather than wireless transmission through internal antenna assemblies.

Correct answers: A, C — The headset is not in discoverable mode.; The headset is out of range or out of battery.

• A. Correct. To be detected during a Bluetooth scan, a device must be in 'discoverable' or 'pairing' mode. If the headset is not actively broadcasting its signal for new connections, the smartphone will not be able to find it.
• B. Incorrect. While NFC (Near Field Communication) can be used for 'tap-to-pair' functionality on some devices, disabling it does not prevent a device from being found during a standard Bluetooth scan.
• C. Correct. Bluetooth has a limited effective range (typically around 10 meters or 30 feet). If the headset is too far away or lacks power due to a dead battery, it will not be able to broadcast the signal required for the smartphone to detect it.
• D. Incorrect. A docking station is typically used for charging or expanding physical ports on a device and is not required for wireless Bluetooth pairing.
• E. Incorrect. USB-C is a physical connection standard. Since the user is attempting to pair a wireless headset, a physical USB connection is not required for the discovery process.

Correct answer: C — 4 centimeters (1.5 inches)

• A. Incorrect. 10 meters is the typical range for Class 2 Bluetooth devices. NFC is designed for extreme proximity to ensure security and prevent accidental connections.
• B. Incorrect. 100 meters is the approximate range for technologies like Wi-Fi or Class 1 Bluetooth. NFC is specifically designed for very short-range communication and cannot operate at this distance.
• C. Correct. NFC is a very short-range wireless technology, typically requiring a distance of 4 cm (about 1.5 inches) or less to initiate a connection. This close proximity helps ensure that data exchange is intentional and secure.
• D. Incorrect. 1 meter is still too far for NFC to function effectively. NFC generally requires devices to be nearly touching or within a few centimeters of each other to establish a link.

Correct answer: C — Airplane mode is currently enabled.

• A. While a hardware failure like a broken antenna could cause connectivity issues, it is highly unlikely to cause a total failure of Wi-Fi, cellular, and Bluetooth signals all at once. Hardware failure is generally a less common cause than user-configurable settings.
• B. A dislodged or missing SIM card will result in a loss of cellular service and data, but it does not disable the phone's ability to connect to Wi-Fi networks or pair with Bluetooth devices.
• C. Airplane mode is specifically designed to disable all wireless communications (cellular, Wi-Fi, and Bluetooth) simultaneously to comply with airline regulations. Given that all three technologies are unavailable at once, this is the most likely and common reason for the connectivity loss.
• D. Being out of range of a Wi-Fi router would explain why the device cannot connect to Wi-Fi, but it would have no impact on cellular reception or the Bluetooth connection to a nearby smartwatch.

Correct answer: C — Force stop the app and clear its cache.

• A. Replacing memory (RAM) is not a practical or necessary step for troubleshooting a single app issue. In most mobile devices, RAM is integrated into the System on a Chip (SoC) and is not user-replaceable. Furthermore, a hardware fault in RAM would manifest as system-wide instability, not just a single app crashing.
• B. A factory data reset is a 'last resort' troubleshooting step because it erases all user data and settings. It is a disproportionate response to an issue isolated to a single application and should only be attempted if all app-level fixes fail.
• C. Force stopping the app and clearing its cache is the standard and most efficient initial step. This resolves issues caused by corrupted temporary data or stuck processes within the app without affecting the rest of the device or user data.
• D. Downgrading the phone's operating system is a complex process that can introduce security vulnerabilities and stability issues. Since the problem is isolated to one specific app, troubleshooting should focus on the app itself rather than changing the entire OS version.

Correct answer: B — DHCP reservation

• A. Port forwarding is used to direct inbound traffic from the internet through a specific port to a specific internal host. While it often requires a device to have a consistent IP, it does not assign or maintain the internal IP address itself.
• B. A DHCP reservation (also known as static DHCP) binds a device's unique MAC address to a specific IP address within the router's DHCP server. This ensures that every time the printer requests an IP address after a power outage or reboot, the router will always assign it the same reserved address.
• C. Dynamic DNS (DDNS) maps a frequently changing public IP address to a consistent domain name, allowing remote users to find a network from the internet. It does not manage or fix internal LAN IP assignments for local devices.
• D. A subnet mask is a configuration that defines the boundary between the network and host portions of an IP address. While it defines the range of available addresses in a network, it cannot ensure that a specific device receives a particular IP.

Correct answer: D — WPA3

• A. WEP (Wired Equivalent Privacy) is an obsolete and insecure wireless security protocol. It uses a weak implementation of the RC4 stream cipher that is easily compromised by modern cracking tools and does not support Simultaneous Authentication of Equals (SAE).
• B. WPA (Wi-Fi Protected Access) was developed as an interim improvement over WEP, utilizing TKIP. While it was more secure than WEP at the time, it is now considered legacy and lacks the advanced encryption and security mechanisms like SAE found in WPA3.
• C. WPA2 (Wi-Fi Protected Access II) implemented the 802.11i standard using AES encryption and CCMP. Although it remains a widely used standard, it uses a 4-way handshake susceptible to offline dictionary attacks and does not support SAE, which was introduced in the subsequent version.
• D. WPA3 (Wi-Fi Protected Access 3) is the most current and secure protocol listed. It introduces Simultaneous Authentication of Equals (SAE) to replace the Pre-Shared Key (PSK) method used in WPA2. SAE provides forward secrecy and protects against offline password-guessing attacks, making it the strongest choice for SOHO network security.

Correct answer: A — Enable a Guest Network with client isolation

• A. Enabling a Guest Network provides a separate network segment for customers, keeping them logically separated from the internal business network where POS systems reside. Client isolation further enhances security by preventing guest devices from communicating with each other, ensuring both business security and customer privacy.
• B. Disabling SSID broadcast (hiding the network name) is a form of security through obscurity. It does not provide true network isolation or security, as the network can still be discovered with the right tools, and once connected, the user would still have access to internal resources if they aren't segmented.
• C. Static IP addresses are used for network management and addressing, not for security or segmentation. Assigning static IPs does nothing to prevent a user from communicating with or attacking other devices on the same or reachable subnets.
• D. Universal Plug and Play (UPnP) is a protocol that allows devices to automatically discover each other and open firewall ports. This actually decreases security and could potentially make it easier for customers to discover and interact with internal systems.

Correct answer: B — Wi-Fi analyzer

• A. A spectrum analyzer is used to detect and visualize raw radio frequency (RF) energy and interference across a range of frequencies. While it can identify signal activity, it is a more specialized tool used for finding non-Wi-Fi interference sources rather than simply identifying Wi-Fi channel assignments.
• B. A Wi-Fi analyzer is specifically designed to scan wireless networks and provide details such as SSID, signal strength, and channel utilization. This tool is the most efficient way to identify co-channel interference caused by multiple access points broadcasting on the same frequency (e.g., Channel 6).
• C. A network tap is a hardware device used to monitor or capture network traffic on a physical wired connection. It is not used for analyzing wireless frequencies or discovering Wi-Fi channel overlap.
• D. An Optical Time-Domain Reflectometer (OTDR) is used to test the integrity and performance of fiber optic cables by measuring light reflection. It has no application in wireless network troubleshooting or RF channel analysis.

Correct answers: A, B — Punchdown tool; Tone generator and probe

• A. Correct. A punchdown tool is used to terminate wire pairs into a keystone jack or patch panel by forcing the wire into the slot and trimming the excess. This tool is essential for the first part of the task: installing the new wall jack.
• B. Correct. A tone generator and probe (also known as a 'fox and hound') are essential for tracing a specific cable through a bundle and identifying its termination in a crowded or messy telecom closet.
• C. Incorrect. A crimper is used to attach RJ-45 or RJ-11 connectors to the ends of cables. While it is used for making patch cables, it is not the tool used for terminating a wall jack (which uses a punchdown) nor for tracing cables in a closet.
• D. Incorrect. A Wi-Fi analyzer is used to measure wireless signal strength, identify interference, and map out wireless coverage. It has no application in installing or tracing physical Ethernet cabling.
• E. Incorrect. A loopback plug is a diagnostic tool used to test the functionality of a network port or network interface card (NIC) by routing the outgoing signal back to the input. It does not assist in cable installation or tracing.

Correct answer: A — 80

• A. Port 80 is the default port for HTTP (Hypertext Transfer Protocol). Because HTTP transmits data in plaintext without encryption, modern browsers display a 'Not Secure' warning. If a user visits a site without specifying 'https://', the browser often defaults to HTTP on port 80 unless a redirect is in place.
• B. Port 443 is the default port for HTTPS (HTTP Secure), which uses SSL/TLS encryption. If the browser were successfully using this port, the user would typically see a padlock icon rather than a 'Not Secure' warning.
• C. Port 22 is assigned to SSH (Secure Shell), a protocol used for secure remote command-line login and administrative tasks. It is not used for standard web browser traffic.
• D. Port 143 is used by IMAP (Internet Message Access Protocol) for retrieving email messages from a server. It is unrelated to web browsing or the 'Not Secure' warning in a browser's address bar.

Correct answer: B — 443

• A. Port 80 is used for HTTP traffic, which is unencrypted and insecure. While it is used for web browsing, it does not meet the requirement for secure e-commerce transactions as data is sent in plain text.
• B. Port 443 is used for HTTPS (HTTP over TLS/SSL) traffic. It encrypts communication between the client and the server, making it the industry standard for secure web browsing and processing e-commerce transactions.
• C. Port 22 is designated for SSH (Secure Shell) connections. While secure, it is used for remote command-line administration and secure file transfers (SFTP), not for public-facing web browsing.
• D. Port 445 is used for SMB (Server Message Block) traffic over TCP/IP, which facilitates file and printer sharing in Windows environments. It is not used to host or serve websites to customers.

Correct answer: B — The CPU fan is not plugged into the CPU_FAN motherboard header

• A. While over-tightening a heat sink can potentially warp the motherboard or damage the CPU socket, it would not trigger a 'CPU Fan Error'. This specific error is related to the motherboard's monitoring of fan RPMs, not mechanical pressure.
• B. The 'CPU Fan Error' and accompanying beeps indicate that the BIOS/UEFI is not detecting a tachometer signal from the device connected to the primary 'CPU_FAN' header. This is a safety feature to prevent the CPU from overheating. This error occurs if the fan is unplugged, faulty, or accidentally plugged into a secondary header like 'SYS_FAN' or 'PWR_FAN'.
• C. Applying thermal paste too thickly or incorrectly can lead to poor heat dissipation and high CPU temperatures, but it does not interfere with the fan detection circuit on the motherboard.
• D. An incompatible CPU usually prevents the system from completing the Power-On Self-Test (POST) or causes it to fail to boot entirely. Because the system is booting and reporting a specific hardware monitoring error, the CPU is likely recognized, but the fan connection is missing.

Correct answer: B — The alignment notch on the bottom edge is in a different position

• A. Incorrect. DDR3 and DDR4 desktop modules (DIMMs) have nearly identical physical lengths. Length is not the mechanism used to prevent incorrect installation.
• B. Correct. Each generation of DDR memory includes a unique 'key' or alignment notch located on the connector edge. The DDR4 notch is in a different position than the DDR3 notch, ensuring that the module cannot be fully seated or locked into an incompatible motherboard slot.
• C. Incorrect. This option reverses the actual specifications; DDR3 DIMMs have 240 pins, while DDR4 DIMMs have 288 pins. Even if the numbers were correct, the differing pin count itself is not what physically blocks the insertion; the notch position does.
• D. Incorrect. While many performance RAM modules use metal heat spreaders (casings), they are used for thermal management, not as a physical keying mechanism. Standard DDR4 modules often have no casing at all.

Correct answer: A — The physical privacy shutter on the webcam

• A. Correct. Many modern webcams include a physical privacy shutter or sliding cover that blocks the camera lens. If this shutter is closed, the device will be detected by the OS and the microphone will function normally, but the video feed will be black. This is the simplest and most common first check for this specific symptom.
• B. Incorrect. The monitor's refresh rate determines how often the image on the screen is updated and is unrelated to the input signal from a USB webcam. A refresh rate issue would not cause a specific video feed within an application to be black while the rest of the display functions.
• C. Incorrect. Speaker volume settings control audio output levels. Since the issue is a lack of video and the audio is reportedly being picked up by the software, adjusting speaker volume will not resolve the black screen.
• D. Incorrect. BIOS/UEFI settings are typically used for low-level hardware initialization. Because the computer is already detecting the USB device (as evidenced by the working audio feed), the hardware is communicating with the OS, making BIOS settings an unlikely and overly complex first troubleshooting step.

Correct answers: A, B, D — Wear an anti-static wrist strap; Hold the CPU by its edges to avoid touching the pins or contacts; Align the orientation indicator on the CPU with the socket

• A. Correct. Wearing an anti-static wrist strap is a fundamental best practice to prevent electrostatic discharge (ESD) from damaging sensitive electronic components like the CPU or motherboard during handling.
• B. Correct. Handling the CPU by its edges minimizes the risk of transferring skin oils or contaminants to the electrical contacts and helps prevent physical damage to delicate pins or pads.
• C. Incorrect. Thermal paste should be applied sparingly to the top of the CPU's integrated heat spreader (IHS), never to the motherboard socket itself. Over-application can lead to poor thermal conductivity or electrical shorts if the paste is conductive.
• D. Correct. Modern CPUs feature orientation indicators, such as a small triangle or notches, to ensure they are seated correctly in the socket. Proper alignment is necessary to prevent permanent damage to the socket pins or the processor.
• E. Incorrect. Modern motherboard sockets (such as ZIF or LGA) are designed so that the CPU drops into place with no force. If resistance is met, the CPU is likely misaligned; applying force will bend pins and destroy the hardware.
• F. Incorrect. Removing the CMOS battery is not a standard or necessary step for the physical installation of a CPU. While it may reset BIOS settings to defaults, it does not facilitate the installation process or protect the hardware.

Correct answer: B — Change the boot order in the BIOS/UEFI settings.

• A. Reinstalling the operating system is unnecessary and destructive. The original boot drive likely still contains the OS; the system is simply failing to target it during the boot process.
• B. This is the most common cause of the error after adding storage hardware. The BIOS/UEFI may have automatically changed the boot priority to the newly installed (and empty) SSD. Adjusting the boot order to prioritize the original drive will allow the system to locate the existing operating system.
• C. Replacing the power supply is incorrect. SSDs have extremely low power consumption. Furthermore, an insufficient power supply would typically result in a failure to POST, random shutdowns, or the system not turning on at all, rather than a specific 'Operating System Not Found' error.
• D. While some motherboards prioritize lower-numbered SATA ports, physically moving the drive is less efficient than simply adjusting the logical boot order in the BIOS/UEFI. If the drive is detected but not booting, the issue is configuration-based rather than port-based.

Correct answer: C — USB Type-C

• A. USB Type-A is the standard, flat rectangular connector commonly found on host devices like PCs and laptops. It is not reversible and must be oriented correctly to be plugged in, which does not match the description.
• B. USB Type-B is typically a larger, more square connector often used on printers, scanners, and older peripherals. It is not small, reversible, or oval-shaped.
• C. USB Type-C is a small, reversible, oval-shaped connector that has become the standard for modern external SSDs and other high-speed devices. Its design allows it to be inserted in either orientation and supports significantly higher data transfer rates and power delivery compared to older USB standards.
• D. Micro-USB is a small connector commonly used for older smartphones and some external drives, but it has a distinct trapezoidal shape and is not reversible.

Correct answer: A — Change the fan control mode in the BIOS from PWM to DC.

• A. Correct. A 3-pin fan lacks the fourth pin required for Pulse Width Modulation (PWM) speed control. Most 4-pin motherboard headers default to PWM mode, which provides a constant 12V to the fan. By changing the BIOS/UEFI setting to DC (Direct Current) mode, the motherboard can regulate the fan speed by varying the voltage supplied to the fan instead, which is compatible with 3-pin connectors.
• B. Incorrect. Moving the fan to another 4-pin header will not solve the problem because the mismatch between the fan's 3-pin connector and the header's control mode (PWM) would persist across all compatible headers until configured in the BIOS.
• C. Incorrect. Thermal paste is used to bridge the microscopic gaps between a processor and its heatsink to improve heat transfer. It has no application for fan connectors and would likely cause electrical or connectivity issues if applied there.
• D. Incorrect. The fan is receiving power, so the power supply is not the issue. The problem is related to the communication and control method between the motherboard header and the fan.

Correct answer: B — 480 Mbps

• A. Incorrect. 12 Mbps is the speed associated with USB 1.1 'Full-Speed' mode. USB 2.0 was designed to provide a much higher data transfer rate than this legacy standard.
• B. Correct. USB 2.0, also known as 'Hi-Speed' USB, has a maximum theoretical data transfer speed of 480 Mbps. This is the standard data rate expected for USB 2.0 on the CompTIA A+ exam.
• C. Incorrect. 5 Gbps (SuperSpeed) is the maximum theoretical data transfer speed of the USB 3.0 standard (also known as USB 3.1 Gen 1 or USB 3.2 Gen 1).
• D. Incorrect. 10 Gbps (SuperSpeed+) is associated with USB 3.1 Gen 2 (or USB 3.2 Gen 2). This speed is significantly higher than the maximum supported by USB 2.0.

Correct answer: C — USB 3.0

• A. USB 1.1 (Full Speed) has a maximum transfer speed of 12 Mbps, which is significantly lower than 5 Gbps. It predates the blue color-coding identification system.
• B. USB 2.0 (High Speed) increased speeds to a theoretical maximum of 480 Mbps. While an improvement over previous versions, it is still far below 5 Gbps and typically uses black or white plastic inserts.
• C. USB 3.0, also branded as SuperSpeed USB (and later renamed to USB 3.1 Gen 1 or USB 3.2 Gen 1), was the first standard to introduce a 5 Gbps theoretical transfer speed. To help users distinguish it from older, slower ports, manufacturers adopted a standard blue plastic insert for the Type-A connectors.
• D. USB 3.2 Gen 2x2 supports speeds up to 20 Gbps using multi-lane operation. While much faster than 5 Gbps, it is a later revision and was not the first to introduce the 5 Gbps threshold.

Correct answer: C — SaaS

• A. Infrastructure as a Service (IaaS) provides the hardware and virtualized resources, but the customer remains responsible for installing and managing the operating system, middleware, runtime environment, applications, and data. This requires the most management among the primary cloud models.
• B. Platform as a Service (PaaS) provides a framework for developers to build and deploy applications. While the provider handles the underlying infrastructure and operating system, the customer is still responsible for managing the applications and data developed on the platform.
• C. Software as a Service (SaaS) delivers software applications managed entirely by the provider. The cloud provider handles the physical infrastructure, operating system, middleware, and the application itself. The customer typically only manages user access and basic settings, resulting in the least amount of IT management responsibility.
• D. Desktop as a Service (DaaS) delivers virtual desktops over the internet. While the provider manages the back-end infrastructure and virtualization layer, the customer is often still responsible for managing the applications installed on those desktops, user profiles, and specific security settings.

Correct answer: B — PaaS

• A. Infrastructure as a Service (IaaS) provides virtualized computing resources such as VMs, storage, and networking. While it offers flexibility, the customer is still responsible for installing and managing the operating system, middleware, and application stack, including manual configuration and patching.
• B. Platform as a Service (PaaS) provides the underlying platform, including the operating system, runtime environments, and web servers. This allows developers to focus entirely on application development and testing without worrying about infrastructure management, OS installation, or patching.
• C. Software as a Service (SaaS) delivers a completed, fully functional software application for end-users. It is not designed to be a development or testing environment where a team can host and run their own custom-built applications.
• D. On-premises solutions require the team to manage everything locally, including physical hardware, networking, virtualization, and all software layers. This represents the maximum amount of maintenance and configuration, which is the opposite of what the team requires.

Correct answer: B — Type 1 hypervisor

• A. A Type 2 hypervisor (e.g., VMware Workstation) runs on top of a host operating system. Because it requires an underlying OS, it is less efficient for datacenter server consolidation and is not installed directly on bare-metal hardware.
• B. A Type 1 hypervisor, also known as a bare-metal hypervisor (e.g., VMware ESXi), is installed directly onto the physical hardware. It allows for the creation and management of multiple virtual machines with minimal overhead, making it the ideal solution for enterprise-level server consolidation.
• C. Virtual Desktop Infrastructure (VDI) is a technology used to host and deliver desktop operating systems to end-users from a centralized server. While it relies on virtualization, it is a deployment model rather than the base software layer installed on bare-metal hardware for server consolidation.
• D. An emulator mimics the hardware of one system to run software designed for another. It typically results in significant performance overhead and is used for compatibility or testing, not for efficiently consolidating production servers.

Correct answer: B — A software-based representation of a physical computer that runs its own operating system.

• A. This describes the physical host machine or server that runs virtualization software, rather than the virtual machine itself.
• B. A virtual machine is a software-based emulation of a physical computer that functions as an independent system, capable of running its own guest operating system and applications.
• C. This describes networking equipment, such as a virtual switch or router, which facilitates communication between networks rather than acting as a computer system.
• D. This refers to cloud storage or backup-as-a-service (BaaS) solutions, which are distinct from the compute environment provided by a virtual machine.

Correct answer: C — Bridged networking

• A. Host-only networking creates a private network that allows communication only between the virtual machines and the host system. It provides no access to the external physical network or the router's DHCP server.
• B. Network Address Translation (NAT) allows the virtual machine to share the host's IP address to access external resources. While this provides internet access, the VM remains on a private internal subnet and does not appear as a unique, separate device to the physical router.
• C. Bridged networking connects the virtual machine's network interface directly to the host's physical network adapter. This makes the VM appear as a distinct node on the local network, allowing it to communicate directly with the physical router and receive its own IP address from the network's DHCP server.
• D. Internal networking isolates the virtual machines so they can only communicate with other VMs on the same host. It disconnects them from both the host system's network stack and the external physical network.

Correct answer: B — Check for continuity between the center pin and the outer shield; there should be none.

• A. Measuring AC voltage is used to check for power-related issues or interference, but it is not a valid method for testing the physical integrity of the cable's insulation or identifying an internal short circuit.
• B. This is the correct procedure. A multimeter set to continuity mode (or resistance/ohms) checks for a complete electrical path. In a functional coaxial cable, the center conductor and the outer shield are physically isolated. Therefore, a test between them should result in no continuity (no beep). If continuity is found, the cable is shorted.
• C. While a continuous beep during a continuity test would indeed confirm the technician's suspicion of a short circuit, this option incorrectly implies that a beep is the expected or 'normal' result of the test. A properly functioning cable should show no continuity between the pin and shield.
• D. Measuring DC voltage is used to verify power delivery in systems like satellite or cable TV (phantom power), but it does not provide information regarding whether the internal conductors are making improper contact.

Correct answer: B — +5V DC

• A. Incorrect. +3.3V DC is typically found on modern SATA power connectors (orange wire) or ATX 20/24-pin motherboard connectors. It is not a standard voltage provided by the 4-pin Molex peripheral connector.
• B. Correct. In a standard legacy 4-pin Molex power connector, the red wire carries +5V DC. This voltage is primarily used to power the logic circuitry of internal peripherals like older hard drives and optical drives.
• C. Incorrect. In a Molex connector, +12V DC is carried by the yellow wire, not the red wire. The yellow lead is used to power mechanical components like motors in drives and cooling fans.
• D. Incorrect. -12V DC is associated with the blue wire on the main 20/24-pin ATX motherboard connector. It is not used or present in a standard 4-pin Molex peripheral connector.

Correct answers: A, B — Cable tester; Loopback plug

• A. A cable tester is used to verify the electrical connections and continuity in a cable run. It can identify opens, shorts, or miswired pins in the Ethernet cable running through the wall, helping to determine if the physical cable is the source of the failure.
• B. A loopback plug is used to test the physical port of a network device, such as a switch or NIC. By plugging it into the switch port in the server room, you can verify if the port hardware is functioning correctly by checking for a link light or signal return.
• C. While a multimeter can measure basic electrical properties like voltage and continuity, it is not specialized for testing multi-pin network cables or digital switch ports. A dedicated cable tester is the industry-standard tool for this purpose.
• D. A Wi-Fi analyzer is designed to troubleshoot wireless signals, signal strength, and channel interference. It provides no diagnostic value for a wired Ethernet drop or physical switch port issue.
• E. A punchdown tool is an installation tool used to terminate copper wires into patch panels or keystone jacks. While it is useful for performing repairs, it is not a diagnostic tool used to identify whether a cable or port is functional.

Correct answer: B — DHCP server is unreachable

• A. Incorrect. DNS (Domain Name System) failure prevents the resolution of hostnames (like google.com) to IP addresses, but it would not cause a computer to assign itself a 169.254.x.x address. If DNS were the issue, the computer would likely still have a valid, routable IP address.
• B. Correct. An IP address in the 169.254.x.x range is an Automatic Private IP Addressing (APIPA) address. This range is automatically self-assigned by Windows when a client is configured for DHCP but fails to receive a response from a DHCP server, indicating the server is unreachable or offline.
• C. Incorrect. A misconfigured default gateway prevents traffic from leaving the local subnet to reach external networks like the internet. However, this does not trigger APIPA; APIPA occurs during the initial IP address acquisition phase when no DHCP lease can be obtained.
• D. Incorrect. While a MAC address conflict (two devices with the same physical address) causes significant network instability and packet loss, it does not lead to the assignment of an APIPA address.

Correct answer: C — Switch

• A. A router operates at Layer 3 (Network Layer) of the OSI model and uses logical IP addresses to forward packets between different networks, whereas Layer 2 deals with MAC addresses on a local segment.
• B. A hub operates at Layer 1 (Physical Layer) and simply broadcasts all incoming data to every port. It does not use MAC addresses or maintain a forwarding table, resulting in a single collision domain.
• C. A switch operates at Layer 2 (Data Link Layer) and uses a MAC address table (CAM table) to direct frames only to the specific port where the destination device is connected, which improves network performance and efficiency.
• D. A repeater operates at Layer 1 (Physical Layer). It functions to regenerate and amplify electrical or optical signals to extend the reach of a network segment beyond its standard cable length limits, without inspecting MAC addresses.

Correct answers: B, D — Clean dust and debris from the cooling vents; Ensure the laptop is used on a hard, flat surface

• A. While an SSD generates less heat than a mechanical HDD, replacing the drive does not address the primary failure of the cooling system responsible for thermal shutdowns.
• B. Dust and debris can block airflow through vents and coat internal heat sinks, preventing proper heat dissipation. Cleaning the cooling system is a primary step in resolving thermal issues.
• C. Upgrading RAM addresses memory capacity and performance issues but does not impact the thermal regulation or physical cooling capabilities of the laptop hardware.
• D. Soft surfaces like beds, couches, or carpets can block the air intake vents usually located on the bottom of a laptop. Using a hard, flat surface allows the laptop's feet to create the necessary clearance for adequate airflow.
• E. Reinstalling the operating system is a software-level fix. While it may resolve issues with high CPU utilization from rogue software, it is not the correct solution for a physical cooling or airflow obstruction.