CompTIA A+ Practice Test (220-1101)

An Uninterruptible Power Supply (UPS) is a backup power supply that can be used in the event of a power outage. Typically a UPS only has 10-15 minutes of power and is intended to allow systems to continue functioning briefly or be powered off safely as opposed to being a long term backup resource.

Reflective segmented LCDs dominate small, battery-powered devices because they consume only microwatts, work well in ambient light without a backlight, and are inexpensive to manufacture. Calculators and basic digital watches almost universally rely on this form of LCD technology. OLED, Plasma, and CRT displays all require far more power (or larger form factors) and therefore are not used in such miniature, low-cost devices.

NFC operates by inductive coupling at 13.56 MHz and is deliberately limited to very short ranges to reduce the risk of eavesdropping. For most consumer devices, the maximum practical distance is about 4 cm (1.6 in) or less; beyond this range the magnetic field is too weak for stable communication. Options that listed 10 cm, 30 cm, or 1 m describe distances associated with other wireless technologies such as RFID or Bluetooth, not NFC.

Warehouses are often dusty, which can clog fans and heatsinks, impeding cooling and promoting overheating. Random freezing and rebooting are classic symptoms of an overheating computer. The high-pitched noise is a strong indicator of a failing fan, which would be the cause of the overheating. These symptoms do not indicate a battery issue or sticky keys. While a bad driver could cause freezing or reboots, it would not explain the physical squealing noise. Therefore, the combination of the symptoms and the environment makes overheating due to a fan issue the most probable cause.

Dynamic Host Configuration Protocol (DHCP) assigns IP's to network devices. Domain Name Service (DNS) translates between IP Addresses and Domain names. Address Resolution Protocol translates between IP Addresses and MAC Addresses (Reverse-ARP, RARP does the opposite)

Cloud-based services, such as those for calendars, email, and contacts, require an active internet connection to synchronize data across devices. Since the user's smartphone has no internet access, the new calendar events it saves locally cannot be uploaded to the cloud service and, therefore, cannot be downloaded by the laptop.

If there are no staple jams, the most common reason a finisher will not staple is that the staple cartridge is empty or not seated correctly. Replacing or reseating the cartridge should restore stapling. Firmware faults or power cycling may resolve other issues but are far less likely when the printer is otherwise functioning normally.

Ports 137 and 139 are associated with NetBIOS/NetBT (NetBIOS over TCP/IP) services. Port 137 is used by the NetBIOS Name Service (NBNS) for name resolution, allowing machines on a local network to find each other by name. Port 139 is used for the NetBIOS Session Service (NBSession), facilitating connection-oriented communication between computers for services like file and print sharing. In modern networks, SMB (Server Message Block) often runs directly over TCP port 445, but these legacy NetBIOS ports are still relevant for backward compatibility. Port 135 is used for RPC Endpoint Mapper and is not directly part of NetBIOS services.

Changing the wireless channel on the router or access point is the most appropriate first step to resolving fluctuations in signal strength due to potential interference from other wireless devices. This type of interference can cause the received signal strength to vary, leading to intermittent connectivity for the client device.

• Updating the laptop's operating system, while potentially helpful for other issues, is not directly tied to improving wireless signal strength consistency.
• Recommending high-gain antennas may help increase wireless signal strength overall but may not address interference problems that cause intermittent connectivity.
• Removing physical obstacles, though potentially beneficial, is moot here because the issue persists even when the laptop's location is unchanged, implying that barriers are not responsible for the fluctuating signal strength.

A Storage Area Network (SAN) is best suited for environments requiring high-performance storage systems that can be accessed and managed centrally. SANs provide dedicated network connectivity to storage pools, ensuring efficient data transfer rates and high availability, which lends itself well to scenarios involving multiple servers requiring access to shared storage resources. It is distinct from NAS devices, which provide file-level storage over networking protocols, and direct-attached storage, which connects storage to a specific server rather than allowing multiple servers to access the storage.

The first step in troubleshooting a problem is to first identify the problem. You will probably be initially given symptoms and then you need to gather information to decipher what the actual problem is.

Creating a virtual machine allows the technician to install Windows XP as a guest operating system inside a hypervisor on the Windows 11 host. The VM abstracts the underlying hardware, so incompatible device drivers on the physical laptop are no longer an issue, and the legacy CAD application can run unmodified. Secure Boot, containers, and dual-booting Windows Server Core do not provide an environment that natively supports Windows XP applications.

Infrastructure as a service (IaaS) is a cloud service model in which the provider supplies the underlying datacenter hardware-servers, storage, and networking-through virtualization. The customer is still responsible for installing and maintaining the operating systems, middleware, and applications that run on top of that hardware.

In industrial settings with dust and vibrations, ruggedized flash drives are created to endure such conditions and are ideal for transporting small-sized data like software updates. Their strong build provides the necessary durability over standard flash drives or external SSDs which, while providing speed, may not have the same level of physical protection. SD cards, although portable, are not inherently designed for rough environments and, without proper handling, are more susceptible to damage. Optical media are sensitive to dust and could be rendered unreadable.

Syslog servers often use port 514 for receiving log messages from various network devices and services. It is important for IT professionals to know common port numbers to configure firewalls, assign permissions, and troubleshoot network communications. While port 389 is typically used by LDAP services and port 162 is for SNMP trap messages, and port 25 is typically used by SMTP services for sending emails, they are not associated with receiving log messages like syslog.

A full-featured USB Type-C cable that supports both USB Power Delivery and DisplayPort Alternate Mode can provide up to 100 W of power, transfer USB 3.x data, and transmit DisplayPort video over the same connection. Standard USB Type-A, HDMI, and RJ-45 cables each support only one of these functions, so they cannot meet all three requirements at once.

Dynamic Host Configuration Protocol (DHCP) is the protocol responsible for assigning IP addresses.

The statement is correct because LCD technology does utilize a backlight to illuminate the liquid crystals that form the image. Without the backlight, the liquid crystals cannot produce a visible image as they do not emit light on their own.

Mini-ITX measures only 170 × 170 mm (6.7 × 6.7 inches), making it the smallest widely adopted consumer motherboard form factor. It is specifically intended for compact builds like home-theater PCs and small-form-factor desktops, yet still accepts standard desktop processors, DIMMs, and one PCIe card. Micro-ATX, ATX, and Extended ATX (EATX) are progressively larger (244 × 244 mm, 305 × 244 mm, and 305 × 330 mm respectively) and would not fit in many HTPC enclosures designed for Mini-ITX boards.

A Community cloud serves multiple organizations with a common interest, providing a shared infrastructure for their specific community. This model helps comply with shared policies and considerations, such as data governance in the case of sensitive research data.