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UP Police Computer Operator study materials
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UP Police Computer Operator practice questions

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Question 1Computer Fundamentals and Organization

In a computer system, which component is commonly described as the 'brain' that fetches, decodes and executes instructions?

  1. The SMPS power supply
  2. The Central Processing Unit Correct answer.
  3. The hard disk drive
  4. The Random Access Memory

Explanation

The CPU performs the fetch-decode-execute cycle and coordinates all other units, which is why it is called the brain of the computer. Storage and memory only hold data and instructions, and the SMPS only supplies regulated DC power.

Question 2Computer Fundamentals and Organization

Which number system is used internally by digital computers because its two states map directly onto transistor ON and OFF conditions?

  1. Hexadecimal
  2. Decimal
  3. Binary Correct answer.
  4. Octal

Explanation

Digital circuits have two stable voltage levels, so data is represented with the two binary digits 0 and 1. Octal and hexadecimal are only shorthand notations used by humans to write binary compactly.

Question 3Computer Fundamentals and Organization

A computer operator wants a storage medium that is non-volatile and uses laser light to read pits and lands on a reflective surface. Which medium fits this description?

  1. Dynamic RAM module
  2. Optical disc such as a CD or DVD Correct answer.
  3. Solid-state USB flash drive
  4. Magnetic tape cartridge

Explanation

Optical discs store data as microscopic pits and lands that are read by a laser beam, and they retain data without power. Magnetic tape and flash memory use magnetic fields and floating-gate cells respectively, not laser reflection.

Question 4Computer Fundamentals and Organization

What is the decimal value of the binary number 1101?

  1. 14
  2. 12
  3. 13 Correct answer.
  4. 11

Explanation

Reading place values from the right, 1101 equals 1×8 + 1×4 + 0×2 + 1×1, which gives 8 + 4 + 0 + 1 = 13. The zero in the twos place contributes nothing to the total.

Question 5Computer Fundamentals and Organization

Which type of software is the operating system of a computer classified as?

  1. System software Correct answer.
  2. Application software
  3. Utility firmware
  4. Programming language

Explanation

An operating system is system software because it manages hardware resources and provides services on which applications run. Application software performs user-oriented tasks, while a programming language is a notation for writing code.

Question 6Computer Fundamentals and Organization

Which unit of memory is exactly equal to 1024 megabytes in the binary convention used by most operating systems?

  1. 1 terabyte
  2. 1 kilobyte
  3. 1 megabit
  4. 1 gigabyte Correct answer.

Explanation

In binary measurement, 1 kilobyte is 1024 bytes, 1 megabyte is 1024 kilobytes, and 1 gigabyte is 1024 megabytes. Each step multiplies by 1024 rather than by 1000.

Question 7Computer Fundamentals and Organization

A candidate is asked to name the register that holds the address of the next instruction to be fetched during the fetch cycle. Which register is it?

  1. Memory Address Register
  2. Program Counter Correct answer.
  3. Instruction Register
  4. Accumulator

Explanation

The Program Counter stores the address of the next instruction, and it is incremented after each fetch so execution proceeds sequentially. The Memory Address Register holds the address currently on the address bus, which may be a data address.

Question 8Computer Fundamentals and Organization

An 8-bit register holds the value 11111111 in two's complement form. What decimal number does it represent?

  1. +255
  2. -128
  3. -1 Correct answer.
  4. +127

Explanation

In two's complement, the most significant bit carries a weight of -128, so 11111111 equals -128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = -1. All ones in an n-bit two's complement register always means -1.

Question 9Computer Fundamentals and Organization

Which cache memory is shared by all cores of a multi-core processor but is still faster than the main RAM?

  1. L2 cache inside each core
  2. The hard disk buffer
  3. L3 cache Correct answer.
  4. L1 cache

Explanation

L3 cache is typically shared across all cores on the chip and sits between the per-core L1 and L2 caches and main memory. L1 and L2 are usually private to each core, and a disk buffer is storage-side memory.

Question 10Computer Fundamentals and Organization

A file is 3 MB in size and the network delivers 6 megabits per second. Approximately how long will the transfer take?

  1. 8 seconds
  2. 0.5 seconds
  3. 24 seconds
  4. 4 seconds Correct answer.

Explanation

3 MB equals 3 × 8 = 24 megabits, because one byte is eight bits. Dividing 24 megabits by 6 megabits per second gives 4 seconds, so the byte-to-bit conversion is the key step.

Question 11Computer Fundamentals and Organization

Which statement correctly distinguishes volatile from non-volatile memory in a computer?

  1. Both types lose their contents on power off, but volatile memory is faster.
  2. Volatile memory loses its contents when power is removed, while non-volatile memory retains them. Correct answer.
  3. Volatile memory is read-only, while non-volatile memory is read-write.
  4. Volatile memory keeps data after power off, while non-volatile memory loses it.

Explanation

Volatility refers to whether stored data survives a power loss. RAM is volatile and loses its contents, whereas ROM, flash and disk retain data without power.

Question 12Computer Fundamentals and Organization

A CPU has a 12-bit address bus. What is the maximum number of distinct memory locations it can address directly?

  1. 8192
  2. 2048
  3. 1024
  4. 4096 Correct answer.

Explanation

With n address lines the processor can select 2^n locations, and 2^12 equals 4096. Each additional address line doubles the addressable space.

Question 13Computer Fundamentals and Organization

Which of these is the correct order of the instruction cycle in a simple CPU?

  1. Fetch, execute, decode, store
  2. Fetch, decode, execute, store Correct answer.
  3. Decode, fetch, execute, store
  4. Execute, fetch, decode, store

Explanation

The processor first fetches the instruction from memory, then decodes its opcode, then executes the operation, and finally stores any result. Decoding before fetching is impossible because the opcode is not yet available.

Question 14Computer Fundamentals and Organization

What is the primary function of the Address Bus in a computer system?

  1. To supply power to the memory chips
  2. To carry the address of the memory location or device being accessed Correct answer.
  3. To carry data between the CPU and memory
  4. To synchronise the clock pulses of the CPU

Explanation

The address bus is unidirectional and carries the address that selects a particular memory cell or I/O device. The actual contents then travel over the separate data bus.

Question 15Computer Fundamentals and Organization

Which of the following best describes the role of the BIOS or UEFI firmware when a computer is switched on?

  1. It performs the power-on self-test and locates a bootable device to start the operating system. Correct answer.
  2. It permanently stores the user's documents between sessions.
  3. It converts source code written in C into machine code.
  4. It loads the user's spreadsheet application into RAM.

Explanation

Firmware stored on the motherboard initialises and tests the hardware, then hands control to a bootloader on a bootable device so the operating system can start. Application loading and compilation happen later, under the operating system.

Question 16Computer Fundamentals and Organization

A technician needs memory that can be erased and reprogrammed electrically while still installed in the circuit, and that retains data without power. Which technology fits best?

  1. DRAM
  2. EEPROM Correct answer.
  3. Mask ROM
  4. SRAM

Explanation

EEPROM can be erased and rewritten electrically in place and is non-volatile, which suits firmware and configuration storage. SRAM and DRAM are volatile, and mask ROM is programmed during manufacture and cannot be rewritten.

Question 17Computer Fundamentals and Organization

Which statement about RISC and CISC processor designs is accurate?

  1. RISC processors cannot use pipelining, while CISC processors always do.
  2. RISC typically uses a small set of simple fixed-length instructions, while CISC favours a larger set of complex variable-length instructions. Correct answer.
  3. CISC designs have no registers, while RISC designs rely only on registers.
  4. CISC typically uses only fixed-length instructions, while RISC uses variable-length ones.

Explanation

RISC emphasises a compact set of simple, usually fixed-length instructions that pipeline well, while CISC offers many complex instructions that may vary in length. Both design families use registers and pipelining.

Question 18Computer Fundamentals and Organization

The hexadecimal number 2F is equivalent to which decimal value?

  1. 47 Correct answer.
  2. 63
  3. 31
  4. 45

Explanation

In hexadecimal, 2F equals 2×16 + 15×1, since F represents 15. This gives 32 + 15 = 47.

Question 19Computer Fundamentals and Organization

A program repeatedly accesses a small loop of instructions that fits entirely inside the L1 cache. What is the most likely performance effect compared with fetching those instructions from main memory each time?

  1. No change occurs because caches store only data and never instructions.
  2. Average access time decreases because cache hits are much faster than main memory accesses. Correct answer.
  3. The CPU clock frequency automatically doubles to compensate.
  4. Average access time increases because cache memory is slower than RAM.

Explanation

Caches exploit locality of reference, and a hit in L1 costs only a few cycles compared with the much longer main-memory latency. Because instruction fetches also pass through the cache hierarchy, a small loop benefits directly.

Question 20Computer Fundamentals and Organization

Which of the following is an example of system software rather than application software on a typical office computer?

  1. A device driver for the printer Correct answer.
  2. A web-based email client
  3. A photo editing suite
  4. A spreadsheet program used for payroll

Explanation

A device driver is system software because it lets the operating system communicate with hardware. Spreadsheets, photo editors and email clients are application software that serve end-user tasks.

Question 21Computer Fundamentals and Organization

A CPU has a 32-bit data bus and a 24-bit address bus. What is the maximum directly addressable memory space, assuming one byte per address?

  1. 8 MB
  2. 4 GB
  3. 16 MB Correct answer.
  4. 32 MB

Explanation

Addressable space depends on the address bus, not the data bus: 2^24 bytes equals 16,777,216 bytes, which is 16 MB. The 32-bit data bus only affects how many bits can be transferred per access.

Question 22Computer Fundamentals and Organization

In a pipelined processor, what does a data hazard occur when?

  1. The branch predictor guesses the wrong target address.
  2. The pipeline clock is running faster than the memory can respond.
  3. Two instructions in different stages try to use the same pipeline stage simultaneously.
  4. An instruction needs a result that a preceding instruction in the pipeline has not yet produced. Correct answer.

Explanation

A data hazard arises from a dependence between instructions, where a later instruction reads an operand before an earlier one has written it. The processor resolves it by forwarding, stalling, or reordering.

Question 23Computer Fundamentals and Organization

Which statement about direct memory access (DMA) is correct?

  1. DMA eliminates the need for an address bus during transfers.
  2. DMA is used only for reading from ROM at boot time.
  3. DMA lets a controller transfer data between an I/O device and memory while the CPU continues other work. Correct answer.
  4. DMA requires the CPU to copy every byte from an I/O device to memory using program instructions.

Explanation

A DMA controller takes over the bus for a block transfer so the CPU is freed from byte-by-byte copying, though the CPU may briefly be held off the bus. Programmed I/O and interrupt-driven I/O are the alternatives that involve the CPU per byte or per block.

Question 24Computer Fundamentals and Organization

A signed 8-bit register holds 10000000 in two's complement. If this value is negated, what result is produced in the same 8-bit register?

  1. 10000000 Correct answer.
  2. 00000000
  3. 11111111
  4. 01111111

Explanation

The value 10000000 represents -128, and negating it mathematically should give +128, which cannot be represented in 8-bit two's complement. The negation wraps around and yields 10000000 again, an overflow case.

Question 25Operating Systems

In a computer operator's daily routine, which component of an operating system is responsible for allocating memory to a newly launched process?

  1. The memory manager Correct answer.
  2. The boot loader
  3. The command interpreter
  4. The device driver

Explanation

The memory manager is the part of the kernel that tracks which regions of RAM are free or in use and assigns space to each process. The command interpreter only reads and executes user commands, device drivers translate requests for hardware, and the boot loader runs before the OS is fully active.

Question 26Operating Systems

A file's permission string on a Linux system reads -rwxr-xr--. What access does the group owner have to this file?

  1. Write and execute
  2. Read only
  3. Read, write and execute
  4. Read and execute Correct answer.

Explanation

The permission string is split into owner, group and others triplets. The group triplet here is r-x, which grants read and execute but not write. The write bit appears only in the owner triplet, so the group cannot modify the file.

Question 27Operating Systems

Which of the following is the primary purpose of virtual memory in a multitasking operating system?

  1. To let programs use more address space than physical RAM provides Correct answer.
  2. To store the BIOS settings permanently on the motherboard
  3. To compress files automatically before they are saved to disk
  4. To increase the clock speed of the processor during heavy load

Explanation

Virtual memory gives each process a large, contiguous address space and pages inactive portions to disk, so programs can exceed available physical RAM. It does not change processor clock speed, hold firmware settings, or perform file compression.

Question 28Operating Systems

Which command in Windows Command Prompt displays the list of files and subdirectories in the current directory?

  1. dir Correct answer.
  2. cd
  3. del
  4. md

Explanation

The dir command lists the contents of the current directory, including file names, sizes and timestamps. The cd command changes the working directory, md creates a directory, and del removes files.

Question 29Operating Systems

An operator needs to stop a running process on a Linux server using its process ID 2451. Which command sends the default termination signal to that process?

  1. kill 2451 Correct answer.
  2. top 2451
  3. ps 2451
  4. rm 2451

Explanation

The kill command with a PID sends a signal, by default SIGTERM, asking the process to terminate. The ps command reports process status, rm deletes files, and top displays live process activity.

Question 30Operating Systems

Which type of operating system is designed so that each task must complete within a guaranteed time limit?

  1. A real-time operating system Correct answer.
  2. A distributed operating system
  3. A batch operating system
  4. A time-sharing operating system

Explanation

A real-time operating system guarantees that critical tasks are completed within defined deadlines, which is essential for control systems and embedded devices. Batch systems run jobs in groups without deadline guarantees, distributed systems spread work across networked machines, and time-sharing systems divide CPU time among interactive users.

Question 31Operating Systems

A user reports that a file named report.txt exists in a directory but cannot be opened for editing. The permission string is -rw-r--r-- and the user is neither the owner nor a member of the group. Which action allows the user to modify the file?

  1. The user renames the file to a different extension
  2. The owner grants others write permission or adds the user to the group with write access Correct answer.
  3. The user copies the file to a new folder and edits the copy
  4. The user logs out and logs back in to refresh permissions

Explanation

The others triplet is r--, so users outside the owner and group can only read the file. Editing requires the write bit, which must be granted either through the others triplet or by adding the user to a group that has write access. Renaming, copying or re-logging in does not change the underlying permission bits.

Question 32Operating Systems

In a paging system, what is the name of the condition in which a process spends more time swapping pages than executing instructions?

  1. Deadlock
  2. Fragmentation
  3. Thrashing Correct answer.
  4. Starvation

Explanation

Thrashing occurs when the working set of active processes exceeds available physical memory, so the system continuously pages data in and out and useful CPU work drops sharply. Fragmentation concerns wasted memory space, starvation concerns indefinite postponement of a process, and deadlock concerns processes waiting on each other's resources.

Question 33Operating Systems

Which scheduling algorithm can cause a long CPU-bound process to wait indefinitely while short processes keep arriving?

  1. Round Robin
  2. Shortest Job First Correct answer.
  3. First In First Out with a single queue
  4. First Come First Served

Explanation

Shortest Job First always picks the process with the smallest burst time, so a long process can be repeatedly overtaken by newly arriving short jobs, a situation known as starvation. FCFS and FIFO serve processes in arrival order, and Round Robin allocates fixed time slices in rotation, so none of these indefinitely postpone a single process.

Question 34Operating Systems

A technician needs to check which disk partitions are mounted and how much space is free on each in a Linux system. Which command provides this information directly?

  1. lsblk -f
  2. df -h Correct answer.
  3. free -h
  4. du -h

Explanation

The df command reports file system disk usage, and the -h flag displays sizes in human-readable units. The du command summarizes space used by files and directories, free reports memory usage, and lsblk lists block devices and file system types without showing free space per mount.

Question 35Operating Systems

What is the main function of a device driver in an operating system?

  1. To translate generic OS requests into commands a specific hardware device understands Correct answer.
  2. To schedule processes across multiple CPU cores
  3. To provide a graphical desktop environment
  4. To manage user login credentials and passwords

Explanation

A device driver is a software layer that converts standard operating system I/O requests into the specific instruction sequences required by a particular piece of hardware. Process scheduling, authentication and desktop rendering are handled by other kernel and user-space components.

Question 36Operating Systems

A Windows user wants to see all running processes and their memory usage from the command line. Which command is appropriate?

  1. ipconfig
  2. tasklist Correct answer.
  3. sfc
  4. chkdsk

Explanation

The tasklist command displays the processes currently running on a Windows system along with details such as memory usage and process IDs. The ipconfig command shows network configuration, chkdsk checks disk integrity, and sfc verifies system files.

Question 37Operating Systems

Which of the following best describes the role of the bootstrap loader during system startup?

  1. It loads the operating system kernel into memory and transfers control to it Correct answer.
  2. It encrypts the hard disk before the OS starts
  3. It allocates IP addresses to network clients
  4. It compiles application source code at boot time

Explanation

The bootstrap loader, stored in firmware or a boot sector, locates the OS kernel, loads it into memory and passes control to it. Encryption of disks, address assignment and code compilation are separate functions performed by other tools or services.

Question 38Operating Systems

A system uses the First Come First Served scheduling algorithm. Three processes arrive at the same time with burst times of 8, 4 and 2 milliseconds. What is the average waiting time?

  1. 4.67 milliseconds Correct answer.
  2. 4.00 milliseconds
  3. 6.00 milliseconds
  4. 14.00 milliseconds

Explanation

In FCFS the processes run in the given order, so waiting times are 0, 8 and 12 milliseconds for the three processes. The sum is 20 milliseconds, and dividing by three processes gives an average of about 4.67 milliseconds.

Question 39Operating Systems

Which file system is the default for modern Windows installations and supports features such as journaling and large file sizes?

  1. FAT32
  2. NTFS Correct answer.
  3. ISO 9660
  4. ext4

Explanation

NTFS is the native file system for modern Windows versions and provides journaling, access control lists and support for very large volumes and files. FAT32 has size limits and lacks journaling, ext4 is a Linux file system, and ISO 9660 is used for optical media.

Question 40Operating Systems

An operator wants to create a compressed archive of a directory on a Linux system using a single command. Which command accomplishes this?

  1. gzip -d backup.tar.gz
  2. cp -r /home/data backup
  3. tar -czvf backup.tar.gz /home/data Correct answer.
  4. tar -xzvf backup.tar.gz

Explanation

The tar command with the c (create), z (gzip compression), v (verbose) and f (file) flags builds a compressed archive from the specified directory. The x flag extracts an archive, gzip -d only decompresses an existing file, and cp copies files without archiving or compression.

Question 41Operating Systems

A system administrator wants to change the priority of a running Linux process so that it receives more CPU time. Which command is used to modify the nice value of an existing process?

  1. renice Correct answer.
  2. chmod
  3. chown
  4. nice

Explanation

The renice command adjusts the nice value of an already running process, which influences how the scheduler prioritizes it. The nice command sets priority only when starting a new process, while chmod and chown change file permissions and ownership.

Question 42Operating Systems

Which of the following is a necessary condition for a deadlock to occur among competing processes?

  1. Preemption of all resources
  2. Round Robin scheduling
  3. Unlimited resource availability
  4. Circular wait Correct answer.

Explanation

Deadlock requires four conditions to hold simultaneously: mutual exclusion, hold and wait, no preemption and circular wait. Circular wait is one of these necessary conditions, whereas preemption of resources and unlimited availability actually prevent deadlock, and Round Robin is a CPU scheduling policy unrelated to deadlock conditions.

Question 43Operating Systems

A process references a page that is not currently in physical memory, and the operating system must load it from disk. What is this event called?

  1. A page replacement
  2. A system call
  3. A page fault Correct answer.
  4. A context switch

Explanation

A page fault occurs when a process accesses a page that is mapped in its virtual address space but not resident in physical memory, prompting the OS to fetch it from disk. A context switch saves and restores process state, a system call requests a kernel service, and page replacement is the policy used to choose which resident page to evict when memory is full.

Question 44Operating Systems

In a system using demand paging with an LRU replacement policy, the reference string is 1, 2, 3, 1, 2 with three frames available. How many page faults occur?

  1. Two
  2. Five
  3. Four
  4. Three Correct answer.

Explanation

The first three references (1, 2, 3) each cause a fault because the frames start empty. The fourth reference to 1 and the fifth reference to 2 both hit, since all three pages remain resident and no eviction is needed. The total is therefore three page faults.

Question 45MS Office and Productivity Software (Word, Excel, PowerPoint, Access)

In MS Word, which keyboard shortcut opens the Find and Replace dialog box directly on the Replace tab?

  1. Ctrl+H Correct answer.
  2. Ctrl+G
  3. Ctrl+R
  4. Ctrl+F

Explanation

Ctrl+H is the standard Word shortcut that opens the Find and Replace dialog with the Replace tab active, so a user can type search and replacement text in one step. Ctrl+F opens the same dialog but lands on the Find tab, which is a different starting point.

Question 46MS Office and Productivity Software (Word, Excel, PowerPoint, Access)

A clerk wants every page of an official report to show the office name and page number at the bottom. Which Word feature should be used?

  1. Endnote
  2. Footnote
  3. Text box on page one
  4. Footer Correct answer.

Explanation

A footer is the area at the bottom margin that repeats on every page of a section, so office name and page number appear automatically throughout the report. Footnotes and endnotes are tied to reference marks in the body text and do not repeat on every page.

Question 47MS Office and Productivity Software (Word, Excel, PowerPoint, Access)

In MS Excel, what does the formula =SUM(A1:A5) do?

  1. Counts the non-empty cells in A1 through A5
  2. Adds the values in cells A1 through A5 Correct answer.
  3. Returns the largest value among A1 through A5
  4. Multiplies the values in A1 through A5

Explanation

The SUM function with a range argument adds all numeric values found in the specified range A1:A5. It ignores text entries in that range rather than treating them as errors.

Question 48MS Office and Productivity Software (Word, Excel, PowerPoint, Access)

Which Excel reference type keeps the column fixed but allows the row to change when a formula is copied down?

  1. A1
  2. A$1
  3. $A1 Correct answer.
  4. $A$1

Explanation

In $A1 the dollar sign before the column letter makes the column absolute while the row number stays relative, so copying the formula down changes the row but copying across keeps column A. This is a mixed reference.

Question 49MS Office and Productivity Software (Word, Excel, PowerPoint, Access)

An operator needs to display only rows where the Department column equals 'Traffic'. Which Excel tool is designed for this?

  1. Filter Correct answer.
  2. Conditional Formatting
  3. Sort
  4. Freeze Panes

Explanation

Filter temporarily hides rows that do not match the criteria, leaving only matching records visible without deleting data. Sorting only reorders rows and does not hide non-matching ones.

Question 50MS Office and Productivity Software (Word, Excel, PowerPoint, Access)

In Excel, which function returns the number of cells in a range that contain numeric values only?

  1. COUNTA
  2. COUNTIF
  3. COUNTBLANK
  4. COUNT Correct answer.

Explanation

COUNT counts only cells holding numbers, ignoring text and blanks. COUNTA counts any non-empty cell, including text, so it answers a different question.