22 Hardware & Mobile Devices Practice Questions & Answers
Every Hardware & Mobile Devices practice question from the CompTIA A+ Practice Test, with the correct answer and a short explanation.
Start practice test →1. In a laser printer, which sequence correctly describes the order of the imaging process?
- A.Processing, charging, exposing, developing, transferring, fusing, cleaning✓ Answer
- B.Charging, processing, developing, exposing, transferring, cleaning, fusing
- C.Charging, exposing, processing, transferring, developing, cleaning, fusing
- D.Processing, exposing, charging, developing, fusing, transferring, cleaning
The printer first rasterizes the page into a bitmap in memory (processing), then a uniform negative charge is applied to the imaging drum (charging). A laser discharges the areas that will hold toner (exposing), toner is attracted to those discharged areas (developing), the toner is pulled onto the paper by the transfer roller (transferring), heat and pressure bond it permanently (fusing), and residual toner and charge are removed before the next page (cleaning). Each stage depends physically on the one before it, which is why the order cannot change.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — printer maintenance: laser imaging processReport a problem with this question
2. Pages from a laser printer look correct, but the toner rubs off the paper when a finger is dragged across the print. Which component is most likely at fault?
- A.Fuser assembly✓ Answer
- B.Imaging drum
- C.Transfer roller
- D.Pickup roller
Toner is a dry plastic powder that only becomes permanent when the fuser melts it into the paper fibers with heat and pressure. If the image is complete and correctly placed, transfer already worked; the failure is at the fusing stage, so a fuser that is not reaching temperature (or a worn fuser) leaves loose toner sitting on the surface.
Source: CompTIA A+ Core 1 exam objectives, Hardware and Network Troubleshooting domain — printer issues (laser fusing stage)Report a problem with this question
3. An inkjet printer produces pages that are missing one color entirely and show horizontal white gaps in that color. What is the correct first maintenance step?
- A.Replace the imaging drum
- B.Replace the fuser assembly
- C.Replace the printer ribbon
- D.Run the printhead cleaning utility✓ Answer
An inkjet forms an image by spraying liquid ink through microscopic nozzles; when ink dries in some of those nozzles the affected color drops out or prints in bands. The cleaning utility forces ink through the nozzles to clear the blockage. Fusers, imaging drums and ribbons belong to laser and impact printers, so they cannot be the cause on an inkjet.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — printer maintenance: inkjet printhead cleaning and calibrationReport a problem with this question
4. A warehouse needs to print multipart carbon-copy forms so that all copies are produced in a single pass. Which printer technology is required?
- A.Inkjet
- B.Laser
- C.Thermal
- D.Impact (dot matrix)✓ Answer
An impact printer drives pins against an inked ribbon and physically strikes the paper, and that mechanical force carries through the carbon or pressure-sensitive layers to every sheet in the form. Laser and inkjet printers deposit toner or ink only on the top sheet, and a thermal printer only darkens chemically treated heat-sensitive paper, so none of them can mark the lower copies.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — printer types and maintenance (impact printers and multipart forms)Report a problem with this question
5. A shared network printer suddenly begins producing pages of random characters and symbols instead of the submitted document. What is the most likely cause?
- A.The paper tray is configured for the wrong paper size
- B.The wrong or a corrupted print driver / page description language is in use✓ Answer
- C.The toner cartridge is nearly empty
- D.The pickup rollers are worn
The driver translates the application's output into the page description language the printer actually understands. If the driver is corrupted, or the queue sends one language to a device expecting another, the printer interprets the data stream as literal characters and prints gibberish. Low toner produces faded output, worn rollers cause feed failures, and a wrong tray size causes jams or prompts, not garbled text.
Source: CompTIA A+ Core 1 exam objectives, Hardware and Network Troubleshooting domain — printer issues (garbled print / driver and page description language)Report a problem with this question
6. Four identical disks are configured as a single RAID 5 array. What usable capacity and fault tolerance does this provide?
- A.The capacity of three disks, surviving the loss of one disk✓ Answer
- B.The capacity of two disks, surviving two simultaneous disk failures
- C.The capacity of two disks, surviving the loss of one disk
- D.The capacity of all four disks, with no fault tolerance
RAID 5 stripes data across all members and distributes parity information among them; the parity consumes the equivalent of exactly one disk, so usable capacity is n-1. Because parity can reconstruct only one missing set of blocks, the array keeps running in a degraded state after one failure, but a second failure before the rebuild completes destroys the array.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — storage devices and RAID configurations (RAID 5 parity)Report a problem with this question
7. Why is RAID 0 an inappropriate choice for data that must survive a drive failure?
- A.It requires a minimum of four drives, which most systems cannot supply
- B.It mirrors every write, which cuts usable capacity in half
- C.It writes all parity to a single dedicated drive, which becomes a bottleneck
- D.It stripes data across every member with no parity and no mirror, so losing any one drive destroys the entire set✓ Answer
RAID 0 exists purely for performance and capacity: blocks of every file are split across the members so reads and writes happen in parallel, and all raw capacity is usable. Because no redundant copy or parity block is stored anywhere, the missing stripes from a single failed member cannot be reconstructed, and the entire volume is lost.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — storage devices and RAID configurations (RAID 0 striping)Report a problem with this question
8. A user accidentally deletes an important project folder from a server volume that is mirrored with RAID 1. What is the correct expectation?
- A.Breaking the mirror will recover the folder from the passive member
- B.The deletion was written to both members instantly, so the folder must be restored from backup✓ Answer
- C.The mirror retains a copy of the deleted folder that can be pulled from the second disk
- D.The RAID controller keeps a deletion log that can be replayed to undo the change
A mirror duplicates every write operation to both members in real time, and a deletion is just another write. RAID protects against hardware failure of a member, not against user error, ransomware or corruption, which is why RAID is fault tolerance and never a substitute for a backup that keeps separate point-in-time copies.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — storage devices and RAID configurations (RAID is fault tolerance, not backup)Report a problem with this question
9. A technician installs a high-performance solid-state drive into a laptop's M.2 slot. The card fits and the drive is detected, but throughput is far below the drive's rating. Documentation shows the slot supports only the SATA protocol. What best explains this?
- A.Physical form factor compatibility does not guarantee full speed; the interface and protocol the slot supports set the ceiling on throughput✓ Answer
- B.The drive's form factor is wrong, so it is operating in a compatibility mode
- C.The drive must be defragmented before it can reach its rated speed
- D.Solid-state drives always run slower in laptops than in desktops
Form factor (the card's physical size and keying), interface (the electrical path, such as SATA or PCIe lanes) and protocol (the command set, such as AHCI over SATA or NVMe over PCIe) are three separate things. A drive attached through a legacy SATA link is capped at that link's bandwidth no matter how fast its flash is, so an NVMe-class drive placed on a SATA-only path performs like a SATA drive.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — storage devices (form factor, interface and protocol distinctions)Report a problem with this question
10. A desktop with a mechanical hard drive has started making a repeated clicking sound, and several files now fail to open. What should the technician do first?
- A.Increase the page file size so the drive is accessed less often
- B.Run a defragmentation pass to relocate the affected files
- C.Update the storage controller driver and keep the system in service
- D.Power the system down and image or replace the drive, because clicking indicates mechanical head or actuator failure✓ Answer
Clicking or grinding on a platter drive means the read/write heads or the actuator are physically failing, and every additional rotation risks scoring the platters and losing more data. The priority is to stop writing to the drive and capture an image while data is still readable; defragmenting or continuing to use the drive multiplies the mechanical wear.
Source: CompTIA A+ Core 1 exam objectives, Hardware and Network Troubleshooting domain — drive issues (grinding and clicking noises)Report a problem with this question
11. A technician installs two identical memory modules in a four-slot desktop board but does not use the slot pair the board documentation specifies. Benchmarks show memory bandwidth roughly half of what was expected. What is the most likely cause?
- A.The modules are not in the matched slot pair, so the memory controller falls back to single-channel operation✓ Answer
- B.Dual-channel operation requires all four slots to be populated
- C.The board is throttling memory because error correction is disabled
- D.One module is defective and is running at reduced capacity
Dual-channel operation widens the path between the memory controller and RAM by addressing two modules in parallel, but it only engages when matched modules sit in the specific slots wired to different channels (usually shown by color coding or labels such as A2 and B2). Put both modules on the same channel and the controller runs single-channel, roughly halving effective bandwidth.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — RAM characteristics (channel configurations and slot population)Report a problem with this question
12. What distinguishes ECC memory from standard non-ECC memory?
- A.It detects and corrects single-bit errors in real time, and requires a board and CPU that support the feature✓ Answer
- B.It runs at a higher clock rate than non-ECC memory of the same generation
- C.It allows modules of different generations to be mixed in the same board
- D.It stores data on the module when the system loses power
ECC modules carry extra memory chips that store check bits, letting the memory controller spot and repair a flipped single bit before the data reaches the CPU. That protection matters where silent corruption is unacceptable, such as servers and workstations, but the controller in the CPU and the board must both support ECC or the feature simply is not used.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — RAM characteristics (ECC vs. non-ECC)Report a problem with this question
13. Two DIMM modules from different DDR generations are the same physical length, yet one will not seat in a board built for the other. Why?
- A.The module will seat but must first be enabled in the firmware setup utility
- B.The key notch is in a different position for each generation, and the memory controller supports only the generation it was designed for✓ Answer
- C.The generations differ only in voltage, so a passive adapter allows the swap
- D.Any DDR module physically fits any DIMM slot; only the achievable speed differs
Each DDR generation places the keying notch at a different point along the contact edge specifically to make cross-generation installation physically impossible. That is deliberate, because the generations use different signalling and voltages and the memory controller is built for one of them; the practical rule is that the module generation must match what the slot and chipset support, and generations can never be mixed in one system.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — RAM characteristics (DIMM/SODIMM form factors and generation compatibility)Report a problem with this question
14. A technician is selecting a motherboard for a workstation that must accept several expansion cards. Which principle should guide the choice of form factor?
- A.Larger board form factors provide more expansion slots, while the smallest ones typically offer only one✓ Answer
- B.All form factors provide the same number of expansion slots; only the mounting holes differ
- C.The smallest form factor should be chosen, because compact boards dedicate more room to expansion
- D.Expansion slot count is determined by the case, not by the motherboard
Motherboard form factors are defined by fixed physical dimensions and mounting-hole patterns, and expansion slots consume board area, so slot count scales with board size: full-size boards carry several slots, mid-size boards fewer, and the smallest boards commonly have a single slot. Since add-on cards plug directly into the board's expansion bus, the form factor decision sets the practical limit on how many cards the system can ever hold.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — motherboards and add-on cards (form factors and expansion slots)Report a problem with this question
15. What is the primary function of a desktop computer's power supply unit?
- A.It regulates the processor's clock speed according to system load
- B.It converts DC from the wall outlet into AC for the motherboard
- C.It converts AC input from the wall into regulated DC output on the 3.3 V, 5 V and 12 V rails✓ Answer
- D.It stores DC power so the system can keep running through a utility outage
Wall power is alternating current, but every component inside the case runs on low-voltage direct current, so the PSU rectifies and regulates the input into stable DC rails. The 12 V rail carries the heaviest loads such as the processor and graphics card, while 5 V and 3.3 V feed lighter logic and drives; battery backup is the job of a UPS, not the PSU.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — power supply (AC input, DC output rails)Report a problem with this question
16. A desktop shuts down or reboots at random, sometimes under heavy load and sometimes at idle. A different application is involved each time, memory tests pass, and temperatures are normal. Which component should be suspected first, and why?
- A.The graphics card, because it draws the most power while the system is idle
- B.The power supply, because degraded or marginal DC output affects every component and produces faults that will not reproduce consistently✓ Answer
- C.The system drive, because random reboots always indicate file system damage
- D.The CMOS battery, because it powers the system while it is idle
Every subsystem draws from the same DC rails, so a supply whose output sags or ripples under changing load can crash whatever component happens to be active at that instant. That is precisely why failing power supplies produce scattered, non-reproducible symptoms rather than one repeatable error, and why substituting a known-good supply is the standard test.
Source: CompTIA A+ Core 1 exam objectives, Hardware and Network Troubleshooting domain — power problems (intermittent shutdowns and random reboots)Report a problem with this question
17. After removing and reinstalling a CPU heat sink without changing the thermal compound, a technician finds the processor reaching high temperatures and slowing under load. What is the correct corrective action?
- A.Clean off the old compound and apply a fresh, thin layer of thermal paste before reseating the heat sink✓ Answer
- B.Reinstall the operating system to clear the performance problem
- C.Raise the processor voltage in the firmware setup so it can push through the slowdown
- D.Add more system memory so the processor has less work to do
Thermal paste exists to fill the microscopic air gaps between the processor's heat spreader and the heat sink base, because air is a poor conductor. Once the joint is broken the cured paste no longer makes full contact, heat cannot move into the sink fast enough, and the CPU protects itself by throttling its clock speed; the fix is always to clean both surfaces and apply fresh compound.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — cooling (thermal paste/pads) and troubleshooting overheatingReport a problem with this question
18. A user connects a computer to a monitor with built-in speakers using a VGA cable. The picture is fine, but no sound comes from the monitor. What explains this?
- A.VGA carries audio only when the display is set to its native resolution
- B.The monitor's digitizer has failed and must be replaced
- C.VGA carries analog video only, so audio must travel over a cable type that carries audio or over a separate audio cable✓ Answer
- D.The graphics card must be replaced before the system can output any audio
Cables should be classified by what signals they actually carry. VGA is a purely analog video interface with no audio pins at all, so no display setting can make it deliver sound. Modern digital display interfaces such as HDMI and DisplayPort carry video and audio on the same cable, which is why switching the connection or adding a dedicated audio cable resolves the symptom.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — cable types and connectors (video cables and the signals they carry)Report a problem with this question
19. A dropped smartphone shows a spiderweb crack across the front glass. The image underneath is bright, complete and correctly colored, but the screen no longer responds to touch. Which part needs replacement?
- A.The main board, because touch input is processed only by the CPU
- B.The camera module, because it shares the front assembly
- C.The digitizer/glass layer, since the display panel itself is still producing a correct image✓ Answer
- D.The battery, because impact damage disables charging circuits
A mobile screen is a stack of separate layers: the display panel generates the image, while the digitizer bonded to the cover glass senses touch. A correct picture proves the panel and its data connection survived, so the failure is isolated to the cracked glass/digitizer layer, which on many devices is replaced as one assembly.
Source: CompTIA A+ Core 1 exam objectives, Mobile Devices and Hardware domains — display components (digitizer/touch layer vs. display panel)Report a problem with this question
20. A user brings in a tablet whose back cover is bulging and no longer sits flat. What is the correct handling?
- A.Press the cover back into place and keep the device in service until a replacement arrives
- B.Puncture the battery to release the trapped gas before removing it
- C.Stop charging, power the device off, avoid pressing or puncturing the battery, and dispose of it as hazardous waste✓ Answer
- D.Put the device on charge overnight to see whether the swelling recedes
Bulging means the lithium-ion cell is generating gas from internal breakdown, and the cell is chemically unstable. Continued charging, physical pressure or puncturing can cause a violent thermal-runaway fire, so the only safe response is to stop using and charging the device and route the battery to hazardous-waste disposal rather than the trash.
Source: CompTIA A+ Core 1 exam objectives, Mobile Devices and Troubleshooting domains — mobile battery issues (swollen battery safety)Report a problem with this question
21. A customer asks for more RAM in a thin-and-light laptop. The service manual lists the memory as part of the mainboard assembly and shows no memory slots. What should the technician tell the customer?
- A.The installed memory capacity can be raised in the firmware setup utility
- B.The RAM is soldered to the board and is not field-replaceable, so more memory requires replacing the mainboard or the laptop✓ Answer
- C.Installing a larger drive will physically increase the amount of installed RAM
- D.A module can be added in the empty memory slot under the keyboard
Field-replaceable parts are the ones the design allows a technician to remove and swap, such as socketed memory modules, drives, wireless cards and batteries. Many ultra-thin systems solder the memory chips directly to the mainboard to save height, which removes the upgrade path entirely; firmware settings and storage capacity cannot substitute for physical memory chips.
Source: CompTIA A+ Core 1 exam objectives, Mobile Devices domain — mobile hardware components and replacement (field-replaceable vs. soldered)Report a problem with this question
22. Which display panel technology produces true black by switching individual pixels off entirely, and for that same reason is prone to burn-in from static images?
- A.IPS
- B.OLED✓ Answer
- C.VA
- D.TN
OLED pixels are self-emissive, so a black pixel simply emits no light and no backlight is needed, which is what allows extremely thin panels and true black levels. The trade-off is that each organic emitter ages with use, so a static element left on screen for long periods wears its pixels unevenly and leaves a permanent ghost. TN, VA and IPS are all LCD variants that modulate a separate backlight and therefore cannot reach a fully off pixel.
Source: CompTIA A+ Core 1 exam objectives, Hardware domain — display components and attributes (OLED vs. LCD panel types)Report a problem with this question
Practice questions written to the published CompTIA A+ Core 1 and Core 2 exam objectives and to standard IT support practice. CompTIA and A+ are marks of CompTIA; this site is not affiliated with or endorsed by CompTIA. The exam objectives are revised periodically — confirm the current objectives and exam requirements with CompTIA before testing. About the CompTIA A+ certification →