Computer Hardware & Memory MCQs With Answers
Knowing what each part inside the box does answers a large share of computer MCQs. These computer hardware and memory MCQs cover the CPU, ALU, control unit and registers, clock speed and multi-core processors, buses, RAM, ROM, cache and virtual memory, volatile and non-volatile storage, hard disks, SSDs, flash drives and optical drives, the motherboard, power supply, graphics and sound cards, ports such as USB, HDMI, VGA, Ethernet and PS/2, and input and output devices from keyboards, mice, scanners and microphones to monitors, printers, plotters and projectors. They are written for PPSC, FPSC, NTS, KPPSC and data entry operator tests.
Take a scored quiz instead →Which component of the Central Processing Unit (CPU) performs arithmetic operations and logical comparisons?
The Arithmetic Logic Unit (ALU) is responsible for executing arithmetic operations (addition, subtraction) and logical evaluations (AND, OR, NOT, comparisons). The Control Unit (CU) directs operations, while Registers provide high-speed temporary storage within the CPU.
Which type of memory is directly accessible by the CPU and retains data temporarily while the system is powered on?
Random Access Memory (RAM) is primary volatile memory accessed directly by the CPU to read and write active program instructions and data. ROM is non-volatile, while HDDs and SSDs are secondary non-volatile storage devices.
What is the small, high-speed memory located inside or near the CPU that bridges the speed gap between the CPU and RAM?
Cache Memory (L1, L2, L3) is an ultra-fast SRAM-based memory located on or near the processor chip. It holds frequently accessed data and instructions to minimize the CPU's wait time when accessing slower RAM.
Which system bus carries physical memory addresses from the processor to RAM or I/O devices?
The Address Bus is unidirectional and specifies the physical location in memory (or I/O port) where data needs to be read from or written to. The Data Bus carries actual data, while the Control Bus transmits control signals like Read/Write commands.
Which semiconductor technology is used to build modern DRAM memory cells, each made of one transistor and one capacitor?
DRAM cells consist of a single MOSFET transistor and a capacitor. Because capacitors leak charge over time, DRAM requires periodic electronic refreshing to maintain stored data.
Which high-speed expansion bus connects the CPU and chipset to graphics cards and NVMe SSDs?
PCI Express (PCIe) is a high-speed serial expansion bus used for graphics cards, NVMe SSDs and network cards.
RAM is connected through the separate memory bus to the memory controller, USB connects external peripherals, and SATA connects hard disks and older SSDs.
Which CPU register holds the memory address of the next instruction waiting to be fetched and executed?
The Program Counter (PC) automatically increments to point to the address of the next instruction to fetch. The Instruction Register (IR) holds the currently executing instruction.
Which storage drive interface standard offers ultra-high throughput by utilizing the PCIe bus directly for solid-state storage?
NVMe is an open host controller interface specifically designed for SSDs connecting directly over high-speed PCIe lanes, bypassing slower legacy SATA controller overhead.
Which of the following devices acts as both an input and an output device?
A Touch Screen Display functions as an input device by sensing physical touch/gestures and as an output device by visually displaying output to the user.
What technology is used by optical mice and barcode scanners to convert light signals into digital data?
Optical devices like optical mice and scanners use photodetectors and light-emitting diodes (LEDs) or lasers to capture reflected light patterns and translate them into digital electrical signals.
Which printer type uses heat to transfer dye onto paper and is commonly used for printing receipts and photo prints?
Thermal printers utilize heat-sensitive paper or thermal ribbons to produce printed images. They are widely used in retail point-of-sale (POS) systems, ATMs, and receipt printing due to their speed and quiet operation.
Which type of storage device has no moving mechanical parts and offers significantly faster read/write speeds than traditional HDDs?
Solid State Drives (SSDs) utilize non-volatile flash memory microchips to store data electronically without any moving mechanical parts, providing faster access times, lower latency, and better durability than traditional Magnetic HDDs.
Which memory is non-volatile and contains built-in startup instructions (BIOS/UEFI) permanently written by the manufacturer?
Read-Only Memory (ROM) is non-volatile memory that permanently retains stored data even when the power is turned off. It holds essential firmware like BIOS needed during computer booting.
What does ‘USB’ stand for in computer hardware technology?
USB stands for Universal Serial Bus. It is an industry standard for cables, connectors, and protocols used for connection, communication, and power supply between computers and peripheral devices.
What keyboard key allows you to cancel an ongoing action, close a popup dialog box, or exit full-screen mode?
The Escape (Esc) key is used to cancel operations, close active dialog boxes, or exit full-screen views (such as stopping video playback or leaving PowerPoint slide view).
What does the abbreviation CPU stand for in computer systems?
CPU stands for Central Processing Unit. It is the primary component of a computer that retrieves, decodes, and executes program instructions. It consists of three main sub-units: the Arithmetic Logic Unit (ALU), the Control Unit (CU), and Registers.
Which component is considered the ‘brain’ of the computer, responsible for executing instructions and processing data?
The Central Processing Unit (CPU) is referred to as the 'brain' of the computer because it performs data processing, system controls, and calculations. Major CPU manufacturers include Intel and AMD, and its speed is measured in Gigahertz (GHz).
Which component of the CPU directs and coordinates all operations of the computer system?
The Control Unit (CU) regulates and manages the timing and data flow between the CPU and other peripherals. It fetches instructions from main memory, decodes them, and coordinates the ALU and storage units to carry out those instructions.
Random Access Memory (RAM) is classified as what type of computer memory?
RAM (Random Access Memory) is volatile primary memory, meaning all stored data is erased when power is lost. It serves as temporary workspace for currently running software applications and operating system processes to enable fast read/write access.
In computer storage, Solid State Drives (SSDs) use which technology unlike traditional Hard Disk Drives (HDDs)?
Solid State Drives (SSDs) use non-volatile flash memory (specifically NAND flash chips) to store data persistently. Unlike traditional Hard Disk Drives (HDDs) that rely on magnetic spinning platters, SSDs have no moving parts, offering significantly faster read/write speeds, lower latency, and higher physical durability.
What is the full form of CD-ROM?
- CD-ROM stands for Compact Disc Read-Only Memory.
- It is an optical disc that stores data.
- Data on a CD-ROM cannot normally be changed.
Which part of the computer is used to permanently store the operating system and files?
- The hard disk stores data permanently, even when powered off.
- It holds the operating system, programs, and files.
- RAM only stores data temporarily.
Which device is used to input handwritten or printed images into a computer?
- A scanner digitizes printed documents or photos.
- It is an input device.
- Scanners are often combined with printers.
Which part of a laptop allows cursor control without an external mouse?
- A touchpad allows cursor control by moving a finger over it.
- It is built into most laptops.
- It works as an alternative to an external mouse.
Which computer component supplies electrical power to internal parts?
- The Power Supply Unit (PSU) converts electricity for internal use.
- It powers the motherboard, CPU, and other parts.
- A weak PSU can cause a computer to malfunction.
Which device is used to project a computer screen onto a large surface for viewing?
- A projector displays a computer's screen on a large surface.
- It is often used for presentations and classrooms.
- Projectors connect to a computer using cables like HDMI.
Which storage device is portable, connects via USB, and is commonly used to transfer files?
- A flash drive is a small, portable USB storage device.
- It is commonly used to transfer or back up files.
- Flash drives come in different storage sizes.
Which port is commonly used to connect a computer to a monitor for high-definition video and audio?
- HDMI connects a computer to a monitor or TV.
- It carries both video and audio through one cable.
- HDMI has replaced older ports like VGA in most devices.
What is the standard layout of most English computer keyboards called?
- QWERTY is the standard keyboard layout in most English keyboards.
- The name comes from the first six letters on the top row.
- Other layouts exist but are far less common.
Which key on a keyboard is used to delete a character to the left of the cursor?
- Backspace deletes a character to the left of the cursor.
- It is commonly used to fix typing mistakes.
- The Delete key removes characters to the right instead.
Which key is used to move the cursor to a new line or confirm an action?
- Enter moves the cursor to a new line or confirms an action.
- It is one of the most frequently used keys.
- It is also used to submit forms on webpages.
Which key locks the keyboard so that letters are typed in uppercase?
- Caps Lock makes all typed letters appear in uppercase.
- Pressing it again turns it off.
- It differs from Shift, which only capitalizes one letter at a time.
Which computer monitor type is thinner and uses less power than older bulky monitors?
- LCD monitors are thin and use less power.
- They replaced older, bulky CRT monitors.
- LED monitors are a newer, more efficient version of LCD technology.
Which older type of monitor was bulky and used a large glass tube?
- CRT monitors were bulky and used a large glass tube.
- They were common before flat-screen monitors became popular.
- CRT monitors have largely been replaced by LCD and LED screens.
Which type of printer uses ink sprayed through tiny nozzles onto paper?
- An inkjet printer sprays tiny drops of ink onto paper.
- It is commonly used for home and small office printing.
- Inkjet printers are known for good photo quality.
Which type of printer uses a laser and toner powder to print documents quickly?
- A laser printer uses a laser and toner powder to print.
- It is known for fast, high-quality text printing.
- Laser printers are common in offices for bulk printing.
What is the memory called that is lost when a computer is turned off?
- Volatile memory loses its data when power is turned off.
- RAM is the most common example of volatile memory.
- Non-volatile memory, like a hard disk, keeps data without power.
Which type of memory keeps its data even after the computer is turned off?
- Non-volatile memory keeps data even without power.
- Hard disks and ROM are examples of non-volatile memory.
- This differs from RAM, which is volatile and loses data.
What is the term for a CPU’s processing speed, usually measured in gigahertz (GHz)?
- Clock speed measures how fast a CPU processes instructions.
- It is usually measured in gigahertz (GHz).
- A higher clock speed generally means faster processing.
What is the term for a processor that has two independent processing units on one chip?
- A dual-core processor has two processing units on one chip.
- It can handle two tasks at the same time.
- More cores generally help with multitasking.
Which computer part processes and improves the display of images, video, and graphics?
- A graphics card processes images, video, and graphics.
- It is important for gaming and video editing.
- Graphics cards can be built-in or added separately.
Which computer part processes and outputs audio, such as music and sound effects?
- A sound card processes and outputs audio from a computer.
- It allows sound to play through speakers or headphones.
- Most modern motherboards have sound built in.
Which part of the computer allows it to connect to a network, either by cable or wirelessly?
- A network card connects a computer to a network.
- It can be wired or wireless.
- Most modern computers have this built into the motherboard.
What is the term for hardware devices such as a keyboard or mouse that are connected to a computer?
- A peripheral is a hardware device connected to a computer.
- Examples include a keyboard, mouse, and printer.
- Peripherals add extra functions beyond the main computer unit.
What is the total number of pixels on a screen, expressed as width by height, called?
- Resolution is the total number of pixels on a screen.
- It is shown as width by height, like 1920x1080.
- Higher resolution means a sharper image.
What is a single point of light that makes up an image on a screen called?
- A pixel is a single point of light on a screen.
- Many pixels together form the images we see.
- More pixels usually means a clearer picture.
What powers a laptop when it is not plugged into an electrical outlet?
- A battery powers a laptop when unplugged.
- It stores electrical energy for portable use.
- Batteries need to be recharged over time.
Which cable type is often used to charge and connect smartphones to a computer?
- A USB cable is commonly used to charge and connect smartphones.
- It also allows data transfer between devices.
- USB cables come in different types, like USB-C and Micro-USB.
Which mouse type uses a light sensor instead of a rolling ball to detect movement?
- An optical mouse uses a light sensor to detect movement.
- It has replaced older mechanical mice with rolling balls.
- Optical mice are generally more accurate and reliable.
What is the older input device called that uses a rotating ball to move the cursor?
- A trackball uses a rotating ball to move the cursor.
- The device itself stays still while the ball is turned.
- It has largely been replaced by the modern mouse.
What is the gaming input device called that uses a stick to control movement?
- A joystick controls movement using a stick.
- It is commonly used for gaming, especially flight simulators.
- Some joysticks are also used in specialized equipment.
What is the device called that captures live video for online video calls?
- A webcam captures live video for calls and streaming.
- Many laptops have a built-in webcam.
- External webcams can connect through USB.
What is the output device called that prints large technical drawings, such as blueprints?
- A plotter prints large technical drawings.
- It is often used for architectural or engineering designs.
- Plotters use pens or special print heads for precise lines.
What is the device called that provides backup power during a power outage?
- A UPS provides backup power during an outage.
- It gives time to save work and shut down safely.
- UPS devices contain a battery for immediate backup power.
What is the device called that reads striped patterns on product packaging at checkout?
- A barcode reader scans striped patterns on products.
- It is widely used in retail checkout systems.
- It quickly identifies products through a connected database.
What is the device called that verifies identity using a fingerprint or face scan?
- A biometric device verifies identity using physical traits.
- Fingerprints and facial features are common examples.
- Many phones use biometric devices to unlock.
What is the term for a computer’s ability to detect and set up new hardware automatically?
- Plug and Play lets a computer detect new hardware automatically.
- It usually requires little or no manual setup.
- Devices like USB drives often work immediately using this feature.
Which part of a computer holds the CPU, RAM, and other components together and lets them communicate?
- The motherboard connects and holds the CPU, RAM, and other parts.
- It allows all major components to communicate.
- Every other hardware part plugs into the motherboard.
Which storage device uses a spinning magnetic disk to read and write data?
- A Hard Disk Drive (HDD) uses a spinning magnetic disk.
- It reads and writes data using a moving arm.
- Solid State Drives are a newer, faster alternative with no moving parts.
Which older, small, portable storage disk was widely used before CDs and USB drives became common?
- A floppy disk was an early, portable storage device.
- It stored much less data than modern storage devices.
- Floppy disks have been replaced by CDs, USB drives, and cloud storage.
Which type of computer memory is used only once during manufacturing and generally cannot be changed later?
- ROM generally cannot be changed after manufacturing.
- It stores permanent instructions like startup data.
- RAM, by contrast, can be freely written to and erased.
Which hardware part cools down the CPU to stop it from overheating?
- A heat sink and fan help cool the CPU.
- Without cooling, the CPU could overheat and get damaged.
- Some high-performance computers use liquid cooling instead.
Which slot on a motherboard is commonly used to add a separate graphics card?
- A PCIe slot is used to add a graphics card to a motherboard.
- It is also used for other add-on cards.
- Graphics cards installed here improve visual processing.
What is the general term for a device that lets a computer send and receive information from the outside world?
- A peripheral device connects to a computer to add function.
- Examples include a mouse, printer, and scanner.
- Peripherals can be input, output, or both.
Which port type was commonly used before USB to connect a keyboard or mouse?
- A PS/2 port was commonly used for keyboards and mice.
- It has largely been replaced by USB ports.
- PS/2 ports are round and have several small pins.
What is the term for the physical case that houses a desktop computer’s internal parts?
- The computer case houses the internal parts of a desktop.
- It protects the motherboard, CPU, and drives.
- Cases come in different sizes depending on the components inside.
What is the term for connecting a laptop to multiple devices, like a monitor and keyboard, using one connector?
- A docking station connects a laptop to many devices at once.
- It uses a single connection point.
- This saves time compared to plugging in each device separately.
Which of the following is most likely to be considered an output device?
- A speaker is an output device because it produces sound.
- Keyboard, mouse, and scanner are input devices.
- Output devices show or produce results for the user.
Which of the following is generally the fastest form of computer memory?
- Cache memory is generally the fastest form of computer memory.
- It is small and located close to the CPU.
- Hard disks and flash drives are much slower by comparison.
Which of the following would most likely be considered an input device?
- A microphone is an input device because it captures sound.
- Monitor, printer, and speaker are output devices.
- Input devices send data into the computer.
Which type of computer memory loses its data when the power is turned off?
- RAM is temporary memory, also called volatile memory.
- It loses all stored data once power is turned off.
- Hard disks and ROM keep data without power.
What does ‘RAM’ stand for?
• RAM is volatile memory that stores data currently being used by the CPU.
• It allows for quick read/write access.
• It loses its data when the power is turned off.
Which memory is ‘non-volatile’?
• Read-Only Memory (ROM) retains data even without power.
• It is used to store firmware and startup instructions (e.g., BIOS).
• It cannot be easily overwritten.
Which input device is most common for text?
• The keyboard is the primary input device for typing.
• It uses a matrix of switches to detect key presses.
• Common layouts include QWERTY.
Which component manages data transfer between memory and processor?
• A bus is a communication system that transfers data between components inside a computer.
• Common types include the Data Bus, Address Bus, and Control Bus.
• The speed of the bus affects overall system performance.
Which unit of measurement is used for processor speed?
• Clock speed is measured in Hertz (e.g., GHz - gigahertz).
• It represents the number of cycles the CPU can execute per second.
• Modern processors typically operate in the multi-gigahertz range.
Which of the following is an ‘Input’ device?
• Scanners convert physical documents or images into digital format.
• Input devices provide data to the computer for processing.
• Examples include keyboards, mice, and microphones.
What is the ‘Main memory’ of a computer?
• RAM is directly accessible by the CPU.
• It is the primary location for storing currently active programs and data.
• Fast access speed is crucial for system performance.
Which port is most common for connecting modern keyboards/mice?
• USB (Universal Serial Bus) is the standard for connecting peripherals.
• It supports 'hot-swapping' (connecting while the computer is on).
• It has replaced older legacy connectors like PS/2.
Which is an ‘Output’ device?
• Monitors display information processed by the computer.
• Output devices translate digital signals into human-readable information.
• Examples include printers and speakers.
Which device protects against power surges?
• A Surge Protector prevents high-voltage spikes from damaging computer components.
• A UPS (Uninterruptible Power Supply) also provides emergency power for shutdown.
• These are essential for delicate electronic hardware.
What is a ‘Register’ in a CPU?
• Registers are located inside the CPU core for immediate data access.
• They are the fastest type of memory in a computer.
• Modern CPUs have a limited number of registers.
Which input device uses light to read characters?
• Optical Character Recognition (OCR) converts images of text into machine-readable format.
• Used for digitizing physical documents.
• Extremely helpful in data entry and archiving.
What is ‘Pipeline’ in CPU architecture?
• Pipelining allows different stages of instruction processing to overlap.
• It significantly increases CPU throughput.
• Each cycle, a new instruction enters the pipeline.
What does ‘SATA’ stand for?
• SATA is the standard interface for connecting storage devices to the motherboard.
• It replaced the older IDE/PATA interface.
• It supports high-speed data transfer.
Which device converts computer data into printed text?
• Printers are essential output devices.
• Laser printers use toner, while inkjet printers use liquid ink.
• 3D printers create physical objects from digital models.
Which device converts analog to digital signal?
An Analog-to-Digital Converter (ADC) samples a continuous analog signal and turns it into discrete digital values, as in microphones, sensors and video capture. A DAC (Digital-to-Analog Converter) does the opposite, for example to drive speakers.
A modem also converts between digital and analog signals when sending data over telephone lines, and a repeater simply regenerates a signal to extend its range.
Which device uses a laser to read optical disks?
• Lasers read the tiny pits and lands on the surface of discs.
• CDs, DVDs, and Blu-rays use this technology.
• Optical media is less common due to the rise of flash storage/streaming.
What is a ‘VGA’ connector?
• VGA (Video Graphics Array) is an older standard for video.
• It carries analog RGB signals.
• It has been replaced by digital standards like HDMI and DisplayPort.
What is ‘Redundancy’ in computing?
• If one component fails, the redundant one takes over immediately.
• Essential for server reliability and data safety.
• Used in RAID arrays and multi-server clusters.
Which input device is used for CAD design?
• Digitizer tablets allow for precise pen-based input.
• Used by artists, engineers, and designers.
• They provide a more natural drawing experience than a mouse.
Which storage medium is ‘Non-volatile’?
• Persistent storage keeps data without electricity.
• HDDs and SSDs store long-term data.
• RAM loses data instantly without power.
What is ‘SSD’?
• SSDs use flash memory.
• Much faster than traditional HDDs.
• Durable with no moving parts.