I85PREP
⌘ K
UPMSP High School Computer study materials
UPMSP High School Computer study resources

UPMSP High School Computer practice questions

One question at a time. Build your UPMSP High School Computer understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Computer Fundamentals and Hardware

Which unit is the smallest addressable storage location in a computer's main memory?

  1. Nibble
  2. Word
  3. Bit
  4. Byte Correct answer.

Explanation

Main memory is organised as a sequence of numbered cells, and each cell holds one byte, so the byte is the smallest unit that can be given its own address. A bit is smaller than a byte but is accessed only as part of a byte, while a word is a larger processing unit whose size varies by processor.

Question 2Computer Fundamentals and Hardware

A computer's ROM is described as non-volatile. What does this mean for the stored contents?

  1. They are erased when the power is switched off
  2. They are copied to RAM before every read operation
  3. They can be changed by any running program at will
  4. They are retained when the power is switched off Correct answer.

Explanation

Non-volatile memory keeps its contents even when electrical power is removed, which is why firmware such as the BIOS is held in ROM. Volatile memory such as RAM loses its data on power-off, and normal programs cannot freely overwrite ROM.

Question 3Computer Fundamentals and Hardware

Which of the following is an input device used to enter handwritten drawings directly into a computer?

  1. Graphics tablet Correct answer.
  2. Speaker
  3. Plotter
  4. Laser printer

Explanation

A graphics tablet uses a stylus on a flat surface to capture the position and pressure of a pen stroke, converting freehand drawing into digital input. Plotters, printers and speakers are output devices that present results rather than accept user input.

Question 4Computer Fundamentals and Hardware

Which of these is an example of system software rather than application software?

  1. Spreadsheet program
  2. Operating system Correct answer.
  3. Photo editor
  4. Web browser

Explanation

System software manages the hardware and provides a platform on which other programs run, and the operating system is its central example. Spreadsheets, browsers and photo editors are application software written to perform tasks for the user.

Question 5Computer Fundamentals and Hardware

In a computer, which component performs arithmetic and logical operations and holds the results temporarily during processing?

  1. Hard disk drive
  2. Arithmetic logic unit Correct answer.
  3. Cache controller
  4. Control unit

Explanation

The arithmetic logic unit, part of the CPU, carries out addition, subtraction, comparisons and logical operations on data held in registers. The control unit directs the sequence of operations instead of performing the calculations itself.

Question 6Computer Fundamentals and Hardware

Which storage medium stores data using laser light and typically offers the largest capacity among the following for a single removable disc?

  1. Floppy disk
  2. Magnetic tape cartridge
  3. DVD Correct answer.
  4. Magnetic hard disk platter

Explanation

A DVD is an optical disc read and written by a laser, and a standard single-layer DVD holds about 4.7 GB, far more than a floppy disk. Magnetic hard disk platters are not removable media in the usual sense and are read magnetically, not by laser.

Question 7Computer Fundamentals and Hardware

Which of the following best describes the function of a computer's motherboard?

  1. It displays text and graphics on the monitor
  2. It converts AC mains supply into regulated DC voltages
  3. It permanently stores the user's documents and programs
  4. It provides the main circuit board connecting the CPU, memory and peripherals Correct answer.

Explanation

The motherboard is the central printed circuit board that carries the chipset, sockets and expansion slots, allowing the processor, memory and input/output devices to communicate. Voltage conversion, permanent storage and display are handled by the power supply, storage drives and graphics output respectively.

Question 8Computer Fundamentals and Hardware

Which number system uses only the digits 0 and 1 and is the natural language of digital circuits?

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

Explanation

Digital circuits use two stable voltage levels, so data is represented with the two symbols 0 and 1, which is the binary system. Octal and hexadecimal are compact shorthand notations derived from binary but use more than two digits.

Question 9Computer Fundamentals and Hardware

What is the decimal value of the binary number 10110?

  1. 22 Correct answer.
  2. 20
  3. 24
  4. 26

Explanation

Reading place values from the left, 10110 equals 16 + 0 + 4 + 2 + 0, which gives 22. Each position doubles in weight from right to left, so the 1s at positions 16, 4 and 2 are summed.

Question 10Computer Fundamentals and Hardware

How many bytes are there in 4 kilobytes when the binary convention of 1 KB = 1024 bytes is used?

  1. 4196
  2. 4000
  3. 4100
  4. 4096 Correct answer.

Explanation

Under the binary convention one kilobyte is 2 raised to the power 10, that is 1024 bytes, so four kilobytes equal 4 multiplied by 1024, giving 4096 bytes. The decimal value 4000 would apply only if 1 KB were defined as exactly 1000 bytes.

Question 11Computer Fundamentals and Hardware

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

  1. 31
  2. 45
  3. 49
  4. 47 Correct answer.

Explanation

In hexadecimal the digit F stands for 15, so 2F equals 2 times 16 plus 15, which is 32 plus 15, giving 47. Each hexadecimal place is a power of sixteen, so the left digit is weighted by 16.

Question 12Computer Fundamentals and Hardware

A student wants to convert the decimal number 45 into binary. Which sequence of bits is correct?

  1. 111001
  2. 101011
  3. 101101 Correct answer.
  4. 110101

Explanation

Subtracting the largest powers of two gives 32 + 8 + 4 + 1, so the bits for positions 32, 16, 8, 4, 2 and 1 are 1, 0, 1, 1, 0 and 1, producing 101101. Checking the sum 32 + 8 + 4 + 1 confirms the value 45.

Question 13Computer Fundamentals and Hardware

Which type of primary memory is directly accessible by the CPU and loses its contents when the computer is switched off?

  1. ROM
  2. Hard disk
  3. RAM Correct answer.
  4. Flash memory

Explanation

RAM is the volatile read-write working memory that the CPU reads and writes while programs run, and its contents vanish on power-off. ROM and flash retain data without power, and a hard disk is secondary storage rather than primary memory.

Question 14Computer Fundamentals and Hardware

What is the main advantage of cache memory over main memory in a computer system?

  1. It is faster and is placed close to the CPU Correct answer.
  2. It is cheaper per byte than main memory
  3. It keeps its contents when power is removed
  4. It has a much larger capacity than main memory

Explanation

Cache memory is built from fast static RAM and sits on or near the CPU, so frequently used instructions and data can be supplied with very low latency. Its capacity is much smaller than main memory and it is more expensive per byte, and it is volatile like RAM.

Question 15Computer Fundamentals and Hardware

In the fetch-decode-execute cycle, what happens during the fetch stage?

  1. The opcode is interpreted to determine the operation
  2. The instruction is brought from memory into the CPU Correct answer.
  3. The result is written back to a register or memory
  4. The ALU calculates the result of the operation

Explanation

During fetch, the address in the program counter is placed on the address bus and the instruction at that address is read into the instruction register. Decoding interprets the opcode, execution performs the operation in the ALU, and writing back stores the result.

Question 16Computer Fundamentals and Hardware

Which of the following is a direct consequence of increasing the clock speed of a processor?

  1. The processor gains more permanent storage capacity
  2. The monitor resolution increases automatically
  3. The size of the main memory increases automatically
  4. The processor completes more cycles per second Correct answer.

Explanation

Clock speed states how many cycles the processor performs each second, so a higher value means more cycles per unit time and, other things being equal, faster instruction throughput. It does not change storage capacity, memory size or display resolution, which depend on different components.

Question 17Computer Fundamentals and Hardware

Which of the following correctly lists the devices in order from fastest to slowest access time?

  1. Cache, main memory, hard disk, magnetic tape Correct answer.
  2. Magnetic tape, hard disk, cache, main memory
  3. Hard disk, cache, main memory, magnetic tape
  4. Main memory, cache, magnetic tape, hard disk

Explanation

Access time grows as storage becomes larger and cheaper, so registers and cache are fastest, main memory is next, a hard disk is slower still, and magnetic tape with its sequential access is slowest. This ordering reflects the memory hierarchy from the CPU outwards.

Question 18Computer Fundamentals and Hardware

A user complains that the computer becomes extremely slow when many programs are open at once, though storage space is plentiful. Which upgrade is most likely to help?

  1. Installing a better printer driver
  2. Adding more RAM Correct answer.
  3. Adding a larger hard disk
  4. Replacing the monitor

Explanation

When many programs run simultaneously and physical RAM is insufficient, the system swaps pages to disk, which slows response dramatically. Adding RAM reduces this swapping and allows more programs to stay resident in memory. Storage is already sufficient and the other options do not affect working memory.

Question 19Computer Fundamentals and Hardware

Which statement correctly distinguishes a compiler from an interpreter?

  1. A compiler translates the whole program before execution, while an interpreter translates and runs line by line Correct answer.
  2. A compiler works only with assembly language, while an interpreter works only with machine code
  3. A compiler runs the source program directly, while an interpreter produces an object file
  4. A compiler needs no memory, while an interpreter needs main memory

Explanation

A compiler processes the entire source program and produces object code before the program runs, whereas an interpreter translates each statement and executes it immediately. This difference affects error reporting and execution speed, not the language used or the need for memory.

Question 20Computer Fundamentals and Hardware

Which logic gate produces an output of 1 only when both of its inputs are 1?

  1. XOR gate
  2. NOT gate
  3. OR gate
  4. AND gate Correct answer.

Explanation

The AND gate outputs 1 only for the input combination 1,1 and outputs 0 for every other combination. The OR gate outputs 1 when at least one input is 1, and the XOR gate outputs 1 only when the inputs differ.

Question 21Computer Fundamentals and Hardware

The binary number 1101 is to be stored in an 8-bit register. What is its 8-bit representation?

  1. 11111101
  2. 10001101
  3. 00001101 Correct answer.
  4. 00011010

Explanation

Padding with leading zeros on the left does not change the value, so the 4-bit pattern 1101 becomes 00001101 in eight bits. Leading zeros simply fill the unused higher-order positions of the register.

Question 22Computer Fundamentals and Hardware

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

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

Explanation

Each address line can carry two states, so n address lines give 2 raised to the power n distinct addresses. For 12 lines this is 2 to the power 12, which equals 4096 locations.

Question 23Computer Fundamentals and Hardware

In a certain system, signed integers are stored in 8-bit two's complement form. What decimal value does the bit pattern 11110110 represent?

  1. -10 Correct answer.
  2. -9
  3. 246
  4. -11

Explanation

The leading bit is 1, so the number is negative; inverting all bits gives 00001001 and adding 1 gives 00001010, which is 10, so the value is -10. Reading the same pattern as unsigned would give 246, but two's complement interpretation makes it negative.

Question 24Computer Fundamentals and Hardware

Why does a computer use a von Neumann architecture's single shared memory for both instructions and data, and what limitation does this create?

  1. It guarantees that programs can never overwrite their own instructions
  2. It removes the need for a control unit because instructions are data
  3. It simplifies design but the same bus must carry instructions and data, so they cannot be fetched simultaneously Correct answer.
  4. It allows unlimited memory expansion without address lines

Explanation

In the von Neumann model, instructions and data share one memory and one set of buses, which keeps the design simple and flexible but means an instruction fetch and a data access cannot occur at the same instant, a bottleneck often called the von Neumann bottleneck. The control unit is still essential, address lines are still required, and self-modifying code remains possible.

Question 25Computer Fundamentals and Hardware

A program repeatedly reads the same small block of data from a large hard disk. Which change would most improve performance, and why?

  1. Adding cache memory, because repeated accesses then avoid the slow disk Correct answer.
  2. Adding a second printer, because output devices share the load
  3. Increasing monitor resolution, because more data can be displayed at once
  4. Increasing disk capacity, because more space allows the block to be stored contiguously

Explanation

Repeated access to the same block exhibits locality of reference, so keeping that block in a fast cache lets subsequent reads be served without touching the disk. Extra capacity does not reduce access time, and display or printing changes do not affect disk read latency.

Question 26Computer Fundamentals and Hardware

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

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

Explanation

An operating system is system software because it manages hardware resources and provides a platform for application programs to run. Application software performs user-oriented tasks, utility software maintains the system, and programming software helps create programs.

Question 27Computer Fundamentals and Hardware

Which of the following is an example of an input device?

  1. Keyboard Correct answer.
  2. Monitor
  3. Speaker
  4. Printer

Explanation

An input device sends data or commands into a computer; a keyboard is a standard input device because it converts key presses into electrical signals for the computer. Monitors, printers, and speakers are output devices because they present results to the user.

Question 28Computer Fundamentals and Hardware

A computer has a 16-bit data bus and a 20-bit address bus. What is the maximum number of distinct memory locations it can address?

  1. 2^20 Correct answer.
  2. 2^36
  3. 2^4
  4. 2^16

Explanation

The number of addressable memory locations is determined by the width of the address bus. With 20 address lines, the processor can generate 2^20 distinct addresses, so the maximum number of locations is 2^20.

Question 29Computer Fundamentals and Hardware

Which of the following correctly describes the main function of a computer's control unit?

  1. It converts high-level language programs into machine code.
  2. It performs arithmetic and logical operations on data.
  3. It stores programs and data permanently.
  4. It directs the operation of the processor by decoding instructions and generating control signals. Correct answer.

Explanation

The control unit fetches instructions, decodes them, and coordinates the other parts of the processor by sending control signals. It does not perform calculations, store data permanently, or translate high-level programs.

Question 30Computer Fundamentals and Hardware

In a computer using memory-mapped I/O, how are input/output devices accessed by the processor?

  1. Through special I/O instructions that use a separate I/O address space.
  2. By using direct memory access (DMA) exclusively, without processor involvement.
  3. Through interrupts only, without any addressable registers.
  4. By treating device registers as memory locations that are read and written with normal memory instructions. Correct answer.

Explanation

Memory-mapped I/O assigns addresses to device registers within the same address space as main memory, so ordinary load and store instructions can access them. This simplifies programming but reduces the address space available for memory.

Question 31Number Systems and Data Representation

In the binary number system, which two symbols are used to represent all values?

  1. 0 and 9
  2. 0 and 1 Correct answer.
  3. 1 and 2
  4. A and B

Explanation

The binary (base-2) system uses only two digits, 0 and 1. Each position in a binary number represents a power of 2, so every value is built from combinations of these two symbols.

Question 32Number Systems and Data Representation

What is the decimal value of the binary number 1011?

  1. 9
  2. 15
  3. 13
  4. 11 Correct answer.

Explanation

Evaluate place values: 1×8 + 0×4 + 1×2 + 1×1 = 8 + 0 + 2 + 1 = 11. Each binary digit is multiplied by the corresponding power of 2 starting from the right.

Question 33Number Systems and Data Representation

How many distinct values can be represented with a 4-bit binary number?

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

Explanation

With n bits the number of distinct patterns is 2^n. For n = 4, that gives 2^4 = 16 values, ranging from 0000 to 1111.

Question 34Number Systems and Data Representation

Which base does the hexadecimal number system use?

  1. 10
  2. 8
  3. 2
  4. 16 Correct answer.

Explanation

Hexadecimal is base 16, using digits 0–9 plus letters A–F to represent values ten through fifteen. It is widely used as a compact shorthand for binary data.

Question 35Number Systems and Data Representation

In the hexadecimal system, which decimal value does the digit F represent?

  1. 14
  2. 16
  3. 15 Correct answer.
  4. 10

Explanation

Hexadecimal digits run 0–9 then A=10, B=11, C=12, D=13, E=14, F=15. The letter F therefore stands for the decimal value fifteen.

Question 36Number Systems and Data Representation

What is the decimal equivalent of the octal number 17?

  1. 9
  2. 15 Correct answer.
  3. 17
  4. 23

Explanation

In base 8, the number 17 means 1×8 + 7×1 = 8 + 7 = 15. Each position represents a power of 8, not a power of 10.

Question 37Number Systems and Data Representation

Convert the decimal number 45 to binary.

  1. 101011
  2. 100101
  3. 101101 Correct answer.
  4. 110101

Explanation

Repeated division by 2 gives remainders 1,0,1,1,0,1 read bottom to top: 101101. Checking: 32+8+4+1 = 45.

Question 38Number Systems and Data Representation

What is the binary representation of the hexadecimal number 2A?

  1. 00110010
  2. 00101010 Correct answer.
  3. 01001010
  4. 00101001

Explanation

Convert each hexadecimal digit into four bits: 2 becomes 0010 and A (10) becomes 1010. Joining them gives 00101010.

Question 39Number Systems and Data Representation

Which binary number is equivalent to the decimal number 100?

  1. 1010100
  2. 1100010
  3. 1101000
  4. 1100100 Correct answer.

Explanation

Powers of 2 summing to 100 are 64 + 32 + 4, giving bits at positions 6, 5 and 2: 1100100. Converting back confirms 64+32+4 = 100.

Question 40Number Systems and Data Representation

What is the hexadecimal equivalent of the binary number 11111111?

  1. 1F
  2. 0F
  3. FF Correct answer.
  4. F0

Explanation

Split the byte into two nibbles: 1111 and 1111. Each nibble equals 15, which is F in hexadecimal, so the result is FF.

Question 41Number Systems and Data Representation

What is the decimal value of the octal number 345?

  1. 189
  2. 231
  3. 229 Correct answer.
  4. 245

Explanation

Expand by powers of 8: 3×64 + 4×8 + 5×1 = 192 + 32 + 5 = 229. Each octal digit carries weight 8^n from right to left.

Question 42Number Systems and Data Representation

Which of these is the 2's complement representation of the decimal number −5 in an 8-bit register?

  1. 00000101
  2. 11111010
  3. 11111011 Correct answer.
  4. 10000101

Explanation

First write +5 as 00000101, then invert all bits to get 11111010, then add 1 to obtain 11111011. This is the standard 2's complement encoding of −5.

Question 43Number Systems and Data Representation

A byte consists of how many bits, and what is its maximum unsigned decimal value?

  1. 8 bits, 256
  2. 8 bits, 255 Correct answer.
  3. 4 bits, 15
  4. 16 bits, 65535

Explanation

One byte is 8 bits, giving 2^8 = 256 distinct patterns. Unsigned values therefore run from 0 to 255.

Question 44Number Systems and Data Representation

Using 8-bit 2's complement, what is the result of adding 01111111 and 00000001?

  1. 10000001, which represents −127
  2. 10000000, which represents −128 due to overflow Correct answer.
  3. 00000000, which represents zero
  4. 11111111, which represents −1

Explanation

01111111 is +127 and adding 1 produces 10000000. In 8-bit 2's complement the sign bit becomes 1, so the value wraps to −128, an overflow case.

Question 45Number Systems and Data Representation

What is the decimal value of the binary fraction 0.101?

  1. 0.75
  2. 0.5
  3. 0.125
  4. 0.625 Correct answer.

Explanation

After the point the weights are 1/2, 1/4 and 1/8. So 0.101 = 1/2 + 0/4 + 1/8 = 0.5 + 0.125 = 0.625.

Question 46Number Systems and Data Representation

How is the decimal number 0.375 represented in binary?

  1. 0.101
  2. 0.001
  3. 0.011 Correct answer.
  4. 0.110

Explanation

Multiply the fraction by 2 repeatedly: 0.375×2 = 0.75 (bit 0), 0.75×2 = 1.5 (bit 1), 0.5×2 = 1.0 (bit 1). Reading the integer parts gives 0.011.

Question 47Number Systems and Data Representation

Which statement correctly describes the binary-coded decimal (BCD) system?

  1. Each decimal digit is coded separately in 4 bits Correct answer.
  2. Only even decimal digits can be encoded
  3. Each bit represents one decimal place
  4. Each decimal digit is converted to its full binary value

Explanation

BCD encodes each individual decimal digit as a 4-bit group, so 27 becomes 0010 0111. This differs from pure binary, where the whole number is converted at once.

Question 48Number Systems and Data Representation

An 8-bit register holds the 2's complement value 11110110. What decimal number does it represent?

  1. −10 Correct answer.
  2. −9
  3. −246
  4. 10

Explanation

The sign bit is 1, so the value is negative. Invert the bits to get 00001001 (9) and add 1 to get 10, so the stored value is −10.

Question 49Number Systems and Data Representation

A binary number has 5 bits. What range of unsigned decimal values can it store?

  1. 0 to 32
  2. 1 to 31
  3. 0 to 31 Correct answer.
  4. 1 to 32

Explanation

For n unsigned bits the range is 0 to 2^n − 1. With n = 5, that is 0 to 32 − 1 = 31.

Question 50Number Systems and Data Representation

Convert the decimal number 0.1 to binary and explain why the result is not exact.

  1. 0.1 exactly, because decimal fractions convert directly
  2. 0.1111… repeating, because all fractions repeat in binary
  3. 0.000110011… repeating, because 0.1 has no finite binary expansion Correct answer.
  4. 0.001 exactly, because 1/8 equals 0.1

Explanation

Multiplying 0.1 by 2 repeatedly never reaches an integer remainder of zero, producing the repeating pattern 000110011…. This is why floating-point representations of 0.1 are approximate.