CompTIA A+ Core 1 — All Questions

Which memory technology is most commonly used as the main system RAM in a modern desktop computer?

• a.GDDR video memory
• b.DDR SDRAM DIMMs✓
• c.NAND flash chips
• d.EEPROM

Modern desktops use DDR SDRAM installed as DIMM modules for main system memory. NAND flash is used for SSDs, GDDR is dedicated video memory on graphics cards, and EEPROM stores small amounts of firmware data.

A technician wants dual-channel memory performance. What is the correct way to install two matching DIMMs?

• a.Populate the matching color-coded slots specified by the board✓
• b.Install one DDR4 and one DDR5 module
• c.Stack them in the first two physical slots only
• d.Place both in adjacent slots regardless of color

Dual-channel mode requires identical modules placed in the color-coded slot pairs the motherboard designates, usually slots 1 and 3 or 2 and 4. Mixing memory generations is impossible because the slots are keyed differently, and simply using adjacent slots may not enable dual channel.

Which storage interface offers the highest sequential throughput for a consumer SSD?

• a.NVMe over PCIe✓
• b.PATA/IDE
• c.SATA III
• d.USB 2.0

NVMe drives communicate over the PCIe bus and greatly exceed the roughly 600 MB/s ceiling of SATA III. USB 2.0 and legacy PATA are far slower and are not used for high-performance internal storage.

What physical form factor is typical for an NVMe solid-state drive installed directly on a motherboard?

• a.PCIe x16 graphics slot
• b.2.5-inch drive bay
• c.5.25-inch bay
• d.M.2 slot✓

Consumer NVMe SSDs commonly use the M.2 gumstick form factor that plugs into a dedicated M.2 slot on the board. The 2.5-inch bay is for SATA SSDs and laptops, while the x16 slot is intended for graphics cards.

A power supply is rated 80 PLUS Gold. What does this rating describe?

• a.The number of PCIe connectors
• b.Physical size of the unit
• c.Maximum wattage output
• d.Energy efficiency at typical loads✓

The 80 PLUS certification tiers (Bronze, Gold, Platinum, etc.) describe how efficiently a PSU converts AC to DC at various load levels. It does not indicate the wattage, connector count, or physical dimensions of the unit.

Which connector supplies dedicated power to a high-end graphics card?

• a.SATA power connector
• b.24-pin ATX
• c.6/8-pin PCIe power connector✓
• d.4-pin Molex to the CPU

Discrete GPUs draw supplemental power through 6-pin or 8-pin PCIe power connectors from the PSU. The 24-pin feeds the motherboard, SATA power feeds drives, and the CPU uses a separate 4/8-pin EPS connector.

What is the primary purpose of thermal paste between a CPU and its heat sink?

• a.To glue the heat sink permanently
• b.To insulate the CPU electrically
• c.To prevent static discharge
• d.To fill microscopic gaps and improve heat transfer✓

Thermal paste fills the tiny air gaps between the CPU integrated heat spreader and the cooler base, improving thermal conduction. It is not an adhesive, an electrical insulator, or an anti-static measure.

Which expansion slot is used by a modern discrete graphics card?

• a.AGP
• b.PCI 32-bit
• c.PCIe x16✓
• d.ISA

Current graphics cards use the PCI Express x16 slot for maximum bandwidth. PCI, AGP, and ISA are legacy interfaces no longer used for new GPUs.

A motherboard's CMOS settings and clock reset every time the PC is unplugged. What is the most likely cause?

• a.Failed CPU
• b.Bad RAM
• c.Depleted CMOS battery✓
• d.Corrupt operating system

The coin-cell CMOS battery (typically a CR2032) maintains BIOS/UEFI settings and the real-time clock when power is removed. When it dies, settings and the clock reset on every power loss.

Which RAID level mirrors data across two drives for redundancy without striping?

• a.RAID 0
• b.RAID 1✓
• c.RAID 10
• d.RAID 5

RAID 1 writes identical copies of data to two drives, providing fault tolerance if one drive fails. RAID 0 stripes without redundancy, RAID 5 uses striping with parity, and RAID 10 combines mirroring and striping.

How many drives are minimally required to build a RAID 5 array?

• a.Four
• b.One
• c.Three✓
• d.Two

RAID 5 distributes parity across all members and needs a minimum of three drives. It can survive the loss of a single drive by rebuilding from parity information.

Which display connector can carry both high-resolution video and audio over a single cable and is common on modern GPUs?

• a.PS/2
• b.VGA
• c.DVI-D
• d.DisplayPort✓

DisplayPort carries digital video and audio and supports high resolutions and refresh rates. VGA is analog video only, DVI-D carries video but not audio, and PS/2 is a keyboard/mouse connector.

What does ECC memory provide that standard memory does not?

• a.Lower power draw
• b.Built-in encryption
• c.Detection and correction of single-bit errors✓
• d.Faster clock speeds

ECC (error-correcting code) memory can detect and correct single-bit errors, which is valuable in servers and workstations. It does not inherently run faster, use less power, or encrypt data.

A technician needs to connect four SATA hard drives but the case lacks power connectors. Which cable adapts available power?

• a.USB-to-Ethernet adapter
• b.Molex-to-SATA power adapter✓
• c.DVI-to-VGA adapter
• d.HDMI splitter

A Molex-to-SATA power adapter converts a legacy 4-pin Molex lead into a SATA power connector for drives. The other adapters handle video or network signals, not drive power.

Which CPU feature allows a single physical core to handle two threads simultaneously?

• a.Simultaneous multithreading (Hyper-Threading)✓
• b.Integrated graphics
• c.Thermal throttling
• d.Overclocking

Simultaneous multithreading, marketed by Intel as Hyper-Threading, lets one core process two instruction threads to improve utilization. Overclocking raises clock speed, throttling reduces it for heat, and integrated graphics is a separate GPU feature.

What is the standard number of pins on the main ATX motherboard power connector?

• a.4 pins
• b.20 pins only
• c.8 pins
• d.24 pins✓

The modern main ATX power connector has 24 pins (a 20-pin base plus a 4-pin extension). The separate CPU EPS connector uses 4 or 8 pins.

Which type of cooling uses a pump, radiator, and liquid to move heat away from the CPU?

• a.Case fan only
• b.Thermal pad
• c.Passive heat sink
• d.Closed-loop liquid cooler (AIO)✓

An all-in-one (AIO) closed-loop liquid cooler circulates coolant through a CPU block to a radiator with fans. A passive heat sink, single case fan, or thermal pad rely on simpler conduction and airflow.

A user reports the PC powers on but there is no display and a repeating beep code sounds. What should the technician consult?

• a.The printer manual
• b.The motherboard/BIOS beep code documentation✓
• c.The Wi-Fi router settings
• d.The event log in Windows

POST beep codes are defined by the BIOS/motherboard vendor and point to hardware faults such as RAM or GPU problems. Because there is no display and the OS has not loaded, Windows logs are unavailable.

Which connector standard is commonly used for internal case front-panel USB 3.x headers?

• a.3.5mm TRS
• b.19/20-pin USB 3.0 header✓
• c.RJ45
• d.PS/2 mini-DIN

Front-panel USB 3.x ports connect to the motherboard through a keyed 19/20-pin internal header. RJ45 is for Ethernet, 3.5mm is audio, and PS/2 is a legacy input connector.

What is the main advantage of a solid-state drive over a traditional hard disk drive?

• a.Uses magnetic platters for redundancy
• b.Larger maximum capacity at lower cost
• c.No moving parts, faster access, and shock resistance✓
• d.Requires no data connection

SSDs store data in flash with no moving parts, giving faster access times and better durability against shock. HDDs still lead on cost per terabyte, but they rely on spinning magnetic platters.

Which component temporarily stores data the CPU is actively using and loses its contents when powered off?

• a.Optical disc
• b.BIOS ROM
• c.Hard drive
• d.System RAM✓

System RAM is volatile memory that holds active program data and is cleared when power is removed. Hard drives and optical discs are non-volatile storage, and BIOS ROM retains firmware.

A technician is asked to install a second GPU for more video ports. Which factor must be verified first?

• a.Number of USB drives
• b.Available PCIe slots and adequate PSU wattage/connectors✓
• c.Monitor cable color
• d.Keyboard layout

Adding a GPU requires a free PCIe x16 slot and a power supply with enough wattage and the correct PCIe power connectors. Peripheral details like cable color or USB drives are irrelevant to installation feasibility.

Which unit describes the rotational speed of a mechanical hard drive that affects its performance?

• a.Watts
• b.Gbps
• c.RPM✓
• d.MHz

Mechanical HDD performance is influenced by platter rotational speed measured in revolutions per minute (e.g., 5400 or 7200 RPM). MHz measures clock frequency, Gbps measures data rate, and watts measure power.

What is the correct anti-static precaution when handling internal PC components?

• a.Wear rubber gloves and touch nothing metal
• b.Work on a carpeted floor barefoot
• c.Rub the component to discharge it
• d.Use an anti-static wrist strap connected to a grounding point✓

An ESD wrist strap bonded to a proper ground equalizes potential and safely dissipates static that could damage components. Carpet increases static, rubbing generates it, and simply wearing rubber gloves does not ground you.