Question Bank — Computer System

NCERT Class 11 Computer Science · Chapter 1 · CBSE Board Pattern

Class 11 Computer Science Chapter 1 Question Bank CBSE Board Pattern

Section A — MCQs (10 questions, 1 mark each)

  1. Which component of the CPU performs all arithmetic and logic operations?
    (a) Control Unit (b) ALU (c) Register (d) Cache
    Answer: (b)

  2. RAM is an example of:
    (a) Non-volatile memory (b) Secondary memory (c) Volatile primary memory (d) Read-only memory
    Answer: (c)

  3. The system bus consists of:
    (a) Only data bus (b) Data bus, address bus and control bus (c) Only address bus (d) Only control bus
    Answer: (b)

  4. Which of the following is NOT an example of system software?
    (a) Operating system (b) Device driver (c) Word processor (d) System utility
    Answer: (c)

  5. Moore’s Law is related to:
    (a) Increase in clock speed of RAM (b) Exponential growth in number of transistors on a chip (c) Increase in size of secondary storage (d) Number of input devices
    Answer: (b)

  6. Assertion (A): ROM is non-volatile memory.
    Reason (R): Contents of ROM are not lost even when power supply is turned off.
    (a) Both A and R are true and R is the correct explanation of A.
    (b) Both A and R are true but R is not the correct explanation of A.
    (c) A is true but R is false.
    (d) A is false but R is true.
    Answer: (a)

  7. Assertion (A): A microcontroller has only CPU on a single chip.
    Reason (R): A microprocessor has CPU, fixed RAM, ROM and other peripherals embedded on a single chip.
    (a) Both A and R are true and R is the correct explanation of A.
    (b) Both A and R are true but R is not the correct explanation of A.
    (c) A is true but R is false.
    (d) A is false but R is true.
    Answer: (d)

  8. Which type of data maintains internal tags or markings to separate data elements but does not follow a strict tabular format?
    (a) Structured data (b) Unstructured data (c) Semi-structured data (d) None of these
    Answer: (c)

  9. The address bus is:
    (a) Bidirectional (b) Unidirectional (c) Used only for writing data (d) Part of secondary memory
    Answer: (b)

  10. Which of the following is an example of application software?
    (a) Compiler (b) Assembler (c) LibreOffice Calc (d) Device driver
    Answer: (c)

Section B — Very Short Answer (6 questions, 2 marks each)

  1. Define the terms bit, nibble and byte as given in the chapter.
  2. Differentiate between RAM and ROM (any two points).
  3. What is the function of the Control Unit (CU) in the CPU?
  4. Name any two input devices and any two output devices mentioned in the chapter.
  5. What is the difference between primary memory and secondary memory?
  6. What is meant by word size of a microprocessor?

Section C — Short Answer (5 questions, 3 marks each)

  1. Explain the role of cache memory in a computer system. How does it help improve CPU performance?
  2. Distinguish between structured data and unstructured data with one example of each from the chapter.
  3. The following pseudocode attempts to describe data transfer using buses. Identify the error and correct it.
    Place address on data bus Send read/write signal on address bus Transfer data on control bus
  4. What are the three types of buses in a computer system? State the purpose of each.
  5. The following code fragment is written to represent memory units. Identify the error and give the correct version.
    1 KB = 1000 Bytes 1 MB = 1000 KB 1 GB = 1000 MB

Section D — Long Answer (3 questions, 5 marks each)

  1. Draw the block diagram of a computer system showing CPU, memory, input/output and storage devices. Explain the function of each component.
  2. Explain the Von Neumann architecture with a labelled diagram. Also describe how data and instructions are stored and executed.
  3. Write an algorithm to transfer data from secondary memory to CPU for processing. Show a dry-run using a trace table for the following steps: (i) load data from secondary storage into RAM, (ii) CPU reads address via address bus, (iii) data placed on data bus, (iv) result written back.

Section E — Case/Source-Based (2 questions, 4 marks each)

Case 1: A school wants to set up a computer laboratory with 20 desktop computers. They need to decide on hardware components, memory types and software.
(a) Which type of memory should be used for temporary storage of running programs and why?
(b) Name two input and two output devices they should install.
(c) Which category of software (system/application) is required to manage all hardware resources? Give one example.
(d) Why is secondary storage necessary even if sufficient RAM is provided?

Case 2: A hospital maintains patient records containing both tabular data and scanned reports.
(a) Classify the tabular attendance-like records as structured/semi-structured/unstructured.
(b) Classify the scanned reports as structured/semi-structured/unstructured.
(c) Which type of memory (primary/secondary) will be used to permanently store these records?
(d) Name the component of the computer system that will control the flow of data between RAM and secondary storage.

▶ Answer Key Attempt all questions first,
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Section A

  1. (b) ALU performs arithmetic and logic operations.
  2. (c) RAM is volatile primary memory.
  3. (b) System bus has three buses.
  4. (c) Word processor is application software.
  5. (b) Moore’s Law predicts transistor growth.
  6. (a) Both true; R correctly explains volatility of ROM.
  7. (d) A is false (microcontroller has peripherals); R is false.
  8. (c) Semi-structured data uses tags.
  9. (b) Address bus carries addresses from CPU to memory (unidirectional).
  10. (c) LibreOffice Calc is application software.

Section B

  1. Bit = binary digit (0/1); Nibble = 4 bits; Byte = 8 bits (two nibbles).
  2. RAM: volatile, used for temporary storage; ROM: non-volatile, stores boot loader permanently.
  3. CU controls sequential instruction execution, interprets instructions and guides data flow.
  4. Input: keyboard, mouse; Output: monitor, printer.
  5. Primary memory (RAM/ROM) has limited capacity and is directly accessed by CPU; secondary memory is non-volatile, larger and cheaper but slower.
  6. Word size = maximum number of bits a microprocessor can process at a time.

Section C

  1. Cache is high-speed memory placed between CPU and RAM; it stores frequently accessed data, reducing average access time from primary memory.
  2. Structured: follows strict record format (e.g., student attendance table); Unstructured: no predefined format (e.g., newspaper or image).
  3. Error: wrong bus used for each task. Corrected:
    Place address on address bus Send read/write signal on control bus Transfer data on data bus
  4. Data bus (bidirectional data transfer), Address bus (unidirectional address transfer), Control bus (control signals).
  5. Error: units use 1024, not 1000. Corrected:
    1 KB = 1024 Bytes 1 MB = 1024 KB 1 GB = 1024 MB

Section D

  1. Block diagram: CPU (ALU + CU + registers) connected to primary memory, input/output devices and secondary storage via system bus. Each component’s function as per chapter.
  2. Von Neumann architecture diagram showing CPU, memory, I/O and communication channels; stored-program concept explained.
  3. Algorithm steps listed; trace table shows each step with address, data bus value and control signal.

Section E

Case 1: (a) RAM (volatile, direct CPU access) (b) Keyboard/mouse; monitor/printer (c) System software – Operating System (d) Secondary storage needed for permanent, larger capacity storage.
Case 2: (a) Structured (b) Unstructured (c) Secondary memory (d) Memory controller / system bus.

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All questions are answerable from the NCERT chapter text. Reviewed by GFIS faculty.