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Punjab PSEB Matric Computer Science study materials
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Punjab PSEB Matric Computer Science practice questions

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Question 1Computer Fundamentals and Hardware

In a microcomputer, which component of the CPU performs addition, subtraction and logical comparisons?

  1. System clock and bus controller
  2. Control unit with its instruction decoder
  3. Main memory and cache together
  4. Arithmetic Logic Unit Correct answer.

Explanation

The arithmetic logic unit (ALU) is the part of the CPU that carries out arithmetic operations such as addition and subtraction and logical comparisons such as AND and OR. The control unit coordinates instruction flow, while memory and clock circuits do not perform calculations.

Question 2Computer Fundamentals and Hardware

A student is told that one kind of memory is volatile. Which storage location is volatile?

  1. Hard disk drive platters
  2. Solid state drive flash chips
  3. Main memory (RAM) Correct answer.
  4. Read only memory chips on the motherboard

Explanation

Volatile memory loses its stored contents when the power supply is removed. RAM is the computer's main volatile working memory, whereas ROM, hard disks and solid state drives keep their data without power.

Question 3Computer Fundamentals and Hardware

Which of these devices is used to produce output from a computer?

  1. Barcode scanner
  2. Optical mouse
  3. Laser printer Correct answer.
  4. Graphics tablet

Explanation

An output device presents processed data to the user. A laser printer produces a printed page, while a graphics tablet, mouse and barcode scanner are input devices that send data into the computer.

Question 4Computer Fundamentals and Hardware

A computer advertisement lists a processor speed of 3.2 GHz. What does this value measure?

  1. Clock cycles the CPU completes each second Correct answer.
  2. Number of pages a laser printer can produce in one minute
  3. Amount of data the hard disk can hold permanently
  4. Capacity of the RAM modules fitted on the motherboard

Explanation

The gigahertz rating of a processor states how many clock cycles it completes each second; 3.2 GHz means 3.2 billion cycles per second. It does not describe disk capacity, RAM size or printer speed.

Question 5Computer Fundamentals and Hardware

Which bus carries the address of a memory location from the CPU to main memory?

  1. Control signal bus
  2. Address bus Correct answer.
  3. Data transfer bus
  4. Electrical power bus

Explanation

The address bus is a one-way set of lines that carries the address of the memory location or I/O port the CPU wants to access. The data bus carries the actual data, and the control bus carries timing and control signals.

Question 6Computer Fundamentals and Hardware

A user wants a backup copy that will survive a lightning strike that destroys the computer. Which choice best meets this requirement?

  1. A folder on the same hard disk
  2. A second partition on the internal hard disk
  3. The computer's RAM
  4. A DVD-R kept in another building Correct answer.

Explanation

An off-site copy on removable media survives fire, flood, theft or a lightning strike that destroys the computer. A second partition or folder on the same hard disk is lost with that disk, and RAM is volatile.

Question 7Computer Fundamentals and Hardware

Which firmware is stored in a ROM chip and begins the computer's startup process?

  1. Device driver
  2. Utility program
  3. Operating system kernel
  4. BIOS Correct answer.

Explanation

BIOS is firmware stored in a ROM chip on the motherboard. During startup it runs the power-on self-test and locates a bootable device before handing control to the operating system.

Question 8Computer Fundamentals and Hardware

What does it mean when a processor is described as 64-bit?

  1. The processor contains exactly 64 independent processing cores
  2. The system clock generates 64 million cycles per second
  3. Registers and data paths handle 64 bits at once Correct answer.
  4. The motherboard can hold a maximum of 64 GB of RAM

Explanation

A 64-bit processor has general-purpose registers and internal data paths that handle 64 bits at a time, which affects how much memory it can address and how it processes data. It does not mean 64 cores, a 64 MHz clock or a 64 GB RAM limit.

Question 9Computer Fundamentals and Hardware

Why is cache memory placed between the CPU and main memory in the memory hierarchy?

  1. It is cheaper per byte than RAM and much larger
  2. It stores the operating system permanently
  3. It is faster than RAM and holds frequently used data Correct answer.
  4. It converts analog signals into digital data

Explanation

Cache is a small, fast memory placed close to the CPU so that frequently used instructions and data can be fetched without waiting for slower main memory. This reduces the average memory access time and keeps the processor busy.

Question 10Computer Fundamentals and Hardware

A computer has 4 GB of RAM installed but a 32-bit operating system cannot use all of it. What is the main reason?

  1. The power supply cannot provide enough current for all four gigabytes
  2. 32-bit addresses cover about 4 GB, part reserved for hardware Correct answer.
  3. The hard disk is partitioned into too few logical drives
  4. RAM modules above 2 GB are not supported by any motherboard

Explanation

A 32-bit processor uses 32-bit addresses, so it can directly address 2^32 bytes, about 4 GB. Part of that address space is reserved for hardware such as the graphics card and chipset, so the operating system cannot use the full 4 GB of installed RAM.

Question 11Computer Fundamentals and Hardware

Which component converts the mains AC supply into the low-voltage DC required by the internal parts of a desktop computer?

  1. The motherboard chipset
  2. The SMPS unit Correct answer.
  3. The hard disk controller
  4. The CPU heat sink fan

Explanation

The switched-mode power supply (SMPS) takes mains alternating current and converts it into the steady low-voltage direct current needed by the motherboard, drives and expansion cards. The other components either process data or remove heat; they do not perform mains-to-DC conversion.

Question 12Computer Fundamentals and Hardware

A user wants a single cable that carries both high-definition video and digital audio from a computer to a monitor. Which port should be used?

  1. RJ-45 port
  2. PS/2 port
  3. HDMI port Correct answer.
  4. VGA port

Explanation

HDMI is a digital interface that carries high-definition video and digital audio over one cable, so a monitor with built-in speakers needs only that connection. VGA carries analog video without audio, while PS/2 and RJ-45 are used for input and networking.

Question 13Computer Fundamentals and Hardware

What is the main reason an SSD usually opens files faster than a magnetic hard disk?

  1. It needs a larger power supply unit
  2. It has no moving read/write heads Correct answer.
  3. It stores data on spinning magnetic platters
  4. It reads data using a laser beam

Explanation

An SSD stores data in flash memory chips and has no spinning platters or moving read/write heads, so it does not wait for mechanical parts to reach the right position. This gives much lower access time than a magnetic hard disk.

Question 14Computer Fundamentals and Hardware

During the fetch stage of the instruction cycle, which register holds the address of the instruction that the CPU will read next?

  1. The instruction register
  2. The status flag register
  3. The program counter Correct answer.
  4. The accumulator

Explanation

The program counter holds the memory address of the next instruction to be fetched. After a fetch, it is normally incremented so that the CPU proceeds to the following instruction, unless a jump changes the sequence.

Question 15Computer Fundamentals and Hardware

A desktop computer loses its date and time every time it is switched off and unplugged. Which component is most likely faulty?

  1. Cache memory
  2. Graphics card
  3. Power supply fan
  4. CMOS battery Correct answer.

Explanation

A small CMOS battery on the motherboard keeps the real-time clock and basic configuration settings alive when the computer is disconnected from mains power. If that battery is flat, the date and time reset on every power loss.

Question 16Computer Fundamentals and Hardware

What is the main job of the chipset on a motherboard?

  1. To execute arithmetic and logic instructions
  2. To store the operating system permanently
  3. To link the CPU with memory and peripherals Correct answer.
  4. To convert alternating current into direct current

Explanation

The chipset provides the connection and control pathways that let the CPU communicate with main memory, storage and peripheral interfaces. It does not itself execute program instructions or convert power.

Question 17Computer Fundamentals and Hardware

Which statement correctly describes static RAM (SRAM)?

  1. It must be refreshed thousands of times each second
  2. It stores each bit in a flip-flop and needs no refresh Correct answer.
  3. It is slower than main memory and used for backups
  4. It is non-volatile and keeps data after power is removed

Explanation

SRAM stores each bit using a flip-flop circuit, so it keeps its value as long as power is supplied without periodic refreshing. This makes it fast enough for cache memory, but it is volatile and more expensive than DRAM.

Question 18Computer Fundamentals and Hardware

A processor is described as a quad-core CPU. What does this mean in practice?

  1. It requires four separate power supplies
  2. It has four times the clock speed of a single core
  3. It can run a maximum of four programs
  4. Four independent processing units share one chip Correct answer.

Explanation

A quad-core processor contains four processing cores in a single package, and each core can work on its own instruction stream. The cores share the same memory and system resources; the label does not multiply clock speed or limit the machine to four programs.

Question 19Computer Fundamentals and Hardware

In the instruction cycle, during which step does the control unit interpret the opcode and decide which operations to perform?

  1. Execute
  2. Decode Correct answer.
  3. Write-back
  4. Fetch

Explanation

In the decode stage, the control unit examines the opcode of the fetched instruction and works out which internal operations and control signals are required. Fetch brings the instruction into the CPU, execute carries it out, and write-back stores the result.

Question 20Computer Fundamentals and Hardware

Which memory chip can keep its contents when power is off and can also be erased and rewritten electrically while still in the computer?

  1. An EEPROM chip Correct answer.
  2. A cache memory block
  3. A mask ROM chip
  4. A DRAM module

Explanation

EEPROM is non-volatile memory whose contents can be erased and reprogrammed electrically while the chip remains in its circuit. Mask ROM is fixed at manufacture, while DRAM and cache lose their contents when power is removed.

Question 21Computer Fundamentals and Hardware

A school office needs to convert printed admission forms into digital image files that can be stored on a computer. Which input device is designed for this task?

  1. Plotter
  2. Projector
  3. Microphone
  4. Scanner Correct answer.

Explanation

A scanner shines light on a printed page and records the reflected pattern as a digital image that can be stored and edited on a computer. A plotter and a projector are output devices, and a microphone captures sound rather than a printed image.

Question 22Computer Fundamentals and Hardware

Why is a heat sink with a fan mounted directly on top of a desktop CPU?

  1. To remove heat produced by the processor Correct answer.
  2. To carry data between the CPU and RAM
  3. To increase the clock speed of the processor
  4. To supply a steady DC voltage to the processor

Explanation

The processor produces heat while it executes instructions, and too much heat can damage it or reduce its reliability. The heat sink conducts heat away from the chip, while the fan moves air to carry that heat out of the case.

Question 23Computer Fundamentals and Hardware

A monitor is advertised as having a resolution of 1920 × 1080. What does this specification describe?

  1. The physical screen size measured in centimetres
  2. The number of times the screen refreshes each second
  3. The maximum number of colours that can be shown at one time
  4. The pixel count in each row and column Correct answer.

Explanation

A resolution of 1920 × 1080 means the display has 1920 pixels across each row and 1080 pixels down each column. Colour depth, physical dimensions and refresh rate are separate specifications.

Question 24Computer Fundamentals and Hardware

Which printer technology uses a rotating drum, toner powder and heat to fix the image onto paper?

  1. Thermal printer
  2. Laser printer Correct answer.
  3. Inkjet printer
  4. Dot-matrix printer

Explanation

A laser printer uses a laser beam to form an electrostatic image on a rotating drum, picks up toner powder and then fuses it onto paper with heat and pressure. Inkjet and thermal printers use different marking methods, and dot-matrix printers strike a ribbon.

Question 25Computer Fundamentals and Hardware

What is the main purpose of the POST that runs immediately after a desktop computer is switched on?

  1. To load the graphical user interface after signing in
  2. To scan the whole computer for viruses at every startup
  3. To test hardware before the operating system starts Correct answer.
  4. To install device drivers for all newly connected hardware

Explanation

The POST (power-on self-test) checks basic hardware such as memory, the processor and connected devices before control is handed to the boot loader. If a fault is found, the computer usually reports it through beeps or a screen message instead of starting the operating system.

Question 26Computer Fundamentals and Hardware

A student wants to add a powerful graphics card to a desktop computer. Which type of motherboard slot is normally used for this card?

  1. A PCI Express x16 slot Correct answer.
  2. A SATA data connector for a hard disk
  3. A DIMM socket used for memory modules
  4. A USB 3.0 port used for pen drives

Explanation

A modern graphics card needs high bandwidth and is normally fitted into a PCI Express x16 slot on the motherboard. SATA connectors are for storage drives, USB ports are external interfaces, and DIMM sockets hold RAM modules.

Question 27Computer Fundamentals and Hardware

A small office wants its desktop computers to keep running for a few minutes during a power cut so that files can be saved. Which device should it install?

  1. A UPS Correct answer.
  2. A power supply unit
  3. A surge protector
  4. A voltage stabilizer

Explanation

A UPS contains a battery and an inverter, so it can supply power for a short time when the mains supply fails. This gives the user time to save work and shut down safely; a surge protector only limits voltage spikes.

Question 28Computer Fundamentals and Hardware

What is the function of a network interface card (NIC) in a desktop computer?

  1. It stores the operating system permanently on the disk
  2. It regulates the voltage supplied to the motherboard
  3. It converts digital signals into sound for the speakers
  4. It links the computer to a network for data transfer Correct answer.

Explanation

A NIC provides the hardware interface that lets a computer send and receive data over a network, using a wired or wireless connection. Sound conversion, permanent storage and voltage regulation are handled by other components.

Question 29Computer Fundamentals and Hardware

During a large file transfer from a hard disk to main memory, direct memory access (DMA) allows the transfer to take place without the CPU handling each byte. What is the main benefit of this arrangement?

  1. The operating system no longer needs any device drivers
  2. The data is automatically compressed before it is transferred
  3. The CPU can do other work during the transfer Correct answer.
  4. The hard disk can store more data in the same physical space

Explanation

With DMA, a dedicated controller moves data between an I/O device and memory while the CPU continues executing other instructions. The CPU is interrupted only when the whole transfer is complete, which improves overall system performance.

Question 30Computer Fundamentals and Hardware

A processor uses an instruction pipeline. What is the main advantage of this design?

  1. Each instruction is completed fully before the next instruction is fetched
  2. The processor can operate without any cache memory being present
  3. The clock speed is deliberately reduced to save electrical power
  4. Several instructions are processed at different stages together Correct answer.

Explanation

In a pipeline, the processor overlaps the stages of several instructions, so while one instruction is being executed another can be decoded and a third fetched. This increases throughput, although it does not make each individual instruction finish faster.

Question 31Computer Fundamentals and Hardware

Which CPU component performs operations such as addition, subtraction and comparisons like greater than?

  1. ALU Correct answer.
  2. Program counter
  3. Instruction register
  4. Control unit

Explanation

The arithmetic logic unit (ALU) carries out arithmetic and logical operations, so it is the part that actually calculates results and makes comparisons. The control unit directs the flow of instructions and data rather than doing the calculations, and the program counter and instruction register are registers that hold addresses and instruction codes.

Question 32Computer Fundamentals and Hardware

A student needs to copy a 25 GB video project to an external drive as quickly as possible using a common desktop port. Which connection should be preferred?

  1. USB 2.0
  2. PS/2
  3. USB 3.0 Correct answer.
  4. VGA

Explanation

USB 3.0 offers much higher data rates than USB 2.0 and is designed for fast external storage, so it transfers a large video project far more quickly. PS/2 is a legacy keyboard and mouse port, and VGA carries video only, so neither can transfer files to an external drive.

Question 33Computer Fundamentals and Hardware

A RAM module is labelled 8 GB DDR4-3200. What does the 8 GB part of the label describe?

  1. Its storage capacity Correct answer.
  2. The voltage the module needs
  3. The number of pins on the module
  4. The speed of the module in MHz

Explanation

In a memory label such as 8 GB DDR4-3200, the first figure is the module's capacity, meaning it can hold about 8 gigabytes of data. The DDR4-3200 part describes the memory generation and its effective data rate, not the capacity.

Question 34Computer Fundamentals and Hardware

A desktop has a 500 W power supply. Its motherboard, CPU, drives and fans are estimated to draw 300 W, and a new graphics card needs 150 W and a 6-pin PCIe power connector. What is the most accurate conclusion?

  1. The total load would be 450 W, so the 500 W supply is adequate if it has the 6-pin connector. Correct answer.
  2. The card cannot be used because its 150 W requirement is greater than the spare capacity left by the other parts.
  3. The power supply will deliver 800 W because the graphics card's wattage is added to the supply's rating.
  4. The card will run without any extra power connector because the slot always supplies all the power it needs.

Explanation

Adding the estimated 300 W system load to the card's 150 W gives 450 W, which is below the 500 W rating. The supply must also provide the required 6-pin PCIe connector, and a small margin is advisable because peak draws can exceed estimates.

Question 35Operating System and File Management

Which function of an operating system is performed when it decides which program receives the CPU next?

  1. Disk defragmentation
  2. Screen resolution setting
  3. File compression
  4. Process scheduling Correct answer.

Explanation

The operating system allocates CPU time among running programs, and the scheduler decides the order in which processes use the processor. Compression, defragmentation, and display settings are separate utility or configuration tasks.

Question 36Operating System and File Management

A user types the command `dir` at a command prompt to list the files in a folder. Which type of user interface is being used?

  1. Voice interface
  2. Graphical user interface
  3. Menu-driven interface
  4. Command-line interface Correct answer.

Explanation

A command-line interface accepts instructions typed as text commands, such as `dir`, and returns text output. A graphical interface relies on windows, icons, and a pointing device instead of typed commands.

Question 37Operating System and File Management

In the filename `report.docx`, what does `docx` indicate?

  1. The folder where the file is stored
  2. The date the file was created
  3. The size of the file in bytes
  4. The file type and its format Correct answer.

Explanation

The extension follows the dot in a filename and identifies the file format, helping the operating system choose an associated application. The folder, size, and creation date are separate pieces of file information.

Question 38Operating System and File Management

A student wants to keep a copy of a file in another folder while leaving the original unchanged. Which operation should be used?

  1. Move
  2. Rename
  3. Delete
  4. Copy Correct answer.

Explanation

Copying creates a duplicate of the selected file in a new location while the original remains in its source folder. Moving transfers the original, renaming changes only the name, and deleting removes the file.

Question 39Operating System and File Management

In the path `C:\Users\Aman\Documents\notes.txt`, which part is the root directory?

  1. `Documents`
  2. `C:\` Correct answer.
  3. `Users`
  4. `notes.txt`

Explanation

The root is the top-level directory of a drive, shown here as the drive letter followed by a backslash. `Users`, `Documents`, and `notes.txt` are lower-level folders or the file itself.

Question 40Operating System and File Management

Which filename would be matched by the search pattern `*.jpg`?

  1. photo.jpg.txt
  2. photo.png
  3. photo.jpg Correct answer.
  4. photo.jpeg

Explanation

In the pattern `*.jpg`, the asterisk stands for any characters before the extension, but the filename must end exactly in `.jpg`. Therefore `photo.jpg` matches, while names with different or extra extensions do not.

Question 41Operating System and File Management

A file deleted from a USB flash drive by pressing Delete may not appear in the Recycle Bin because:

  1. deleted files are always compressed
  2. the Recycle Bin stores only system files
  3. the file is converted into a shortcut
  4. removable drives often skip the Recycle Bin Correct answer.

Explanation

Windows commonly treats deletion on removable drives differently from fixed internal drives, so files may be removed permanently instead of being held in the Recycle Bin. The Recycle Bin can hold ordinary files and folders, not only system files.

Question 42Operating System and File Management

Which file attribute, when set, prevents a file from being changed but still allows it to be read?

  1. Archive
  2. Read-only Correct answer.
  3. Hidden
  4. System

Explanation

The read-only attribute blocks editing or saving changes to the file while still permitting users to open and read it. Hidden, archive, and system attributes serve different purposes in file management.

Question 43Operating System and File Management

A single-core CPU runs a word processor and a music player by rapidly switching between them. Which term describes this operating-system capability?

  1. Booting
  2. Formatting
  3. Multitasking Correct answer.
  4. Multiprocessing

Explanation

Multitasking allows one CPU to switch rapidly among several programs, giving each a short time slice so they appear to run at the same time. Multiprocessing instead requires multiple processors working in parallel.

Question 44Operating System and File Management

Why must a `.zip` file usually be extracted before the individual files inside it can be edited normally?

  1. A zip file is a folder that can be edited directly
  2. A zip file is a shortcut to the original files
  3. A zip file holds compressed data needing expansion Correct answer.
  4. A zip file is a virus that blocks editing

Explanation

A zip archive stores one or more files in a compressed form, so extraction is needed to restore usable copies of the contents. After extraction, the resulting files can be opened and edited with their associated applications.

Question 45Operating System and File Management

Which of the following is an example of system software?

  1. VLC media player
  2. Windows 10 Correct answer.
  3. Adobe Photoshop
  4. MS Word

Explanation

System software is the set of programs, such as the operating system and its utilities, that controls the hardware and provides the platform on which other programs run. Windows 10 is an operating system, so it belongs to this category, while word processors, image editors and media players are application software written to perform user tasks.

Question 46Operating System and File Management

The process of loading the operating system from secondary storage into main memory when a computer is switched on is known as:

  1. Booting Correct answer.
  2. Spooling
  3. Swapping
  4. Formatting

Explanation

Booting is the startup sequence in which the firmware runs a power-on self-test and then a boot loader reads the operating system from secondary storage and loads it into RAM. Only after this process does the operating system take control of the computer's memory, processor and devices.

Question 47Operating System and File Management

A folder that is created inside another folder is known as a:

  1. Root folder
  2. Subfolder Correct answer.
  3. Shortcut
  4. Archive

Explanation

A folder created inside another folder is a subfolder, and it sits one level below its parent in the directory tree. The topmost folder of a drive is the root folder, which has no parent above it.

Question 48Operating System and File Management

When main memory (RAM) becomes full, the operating system may temporarily move some inactive data to a reserved area on the hard disk. This reserved area is called the:

  1. Cache memory
  2. Registry
  3. BIOS
  4. Swap file Correct answer.

Explanation

The swap file, also called the page file, is disk space that the operating system uses as an extension of RAM, moving inactive pages out when RAM is full and bringing them back when they are needed again. This lets programs larger than physical memory run, although access is much slower than reading from RAM.

Question 49Operating System and File Management

Which list arranges the units of file size correctly from smallest to largest?

  1. Megabyte, Kilobyte, Terabyte, Gigabyte
  2. Kilobyte, Megabyte, Gigabyte, Terabyte Correct answer.
  3. Kilobyte, Gigabyte, Megabyte, Terabyte
  4. Terabyte, Gigabyte, Megabyte, Kilobyte

Explanation

File sizes are measured in bytes, and each larger unit is roughly one thousand times the previous one: a kilobyte is about 1,024 bytes, a megabyte about 1,024 kilobytes, a gigabyte about 1,024 megabytes and a terabyte about 1,024 gigabytes. The order therefore runs kilobyte, megabyte, gigabyte, terabyte.

Question 50Operating System and File Management

A utility program that rearranges the scattered pieces of files on a hard disk so that each file is stored in continuous locations is called a:

  1. Disk cleanup utility
  2. Backup and restore tool
  3. Disk defragmenter Correct answer.
  4. Antivirus scanning tool

Explanation

A disk defragmenter is a utility that rearranges the pieces of files scattered across a hard disk so that each file occupies continuous clusters. Sequential reading then requires less head movement, which improves access speed on traditional magnetic hard disks.