• Class: Seven

    Chapter 1: Computer Hardware

    Exercise Solution

    1. Fill in the blanks:

    a) A Keyboard is the standard input device.
    b) Keyboard was invented by Christopher Latham Sholes.
    c) The quality of image captured by Digital Camera is measured in Pixels.
    d) Ports are sockets that are used to connect external devices.

    2. Select the most suitable alternative:

    a) What does a computer system consist of?
    (i) Input Devices          (ii) Output Devices      (iii) Processing Devices       (iv) All of these 

    b) Which of the following is/are input device/s?
    (i) Light Pen                 (ii) Microphone            (iii) Bar Code Readers         (iv) All of these 

    c) Which of the following looks like a typewriter machine?
    (i) Keyboard                 (ii) Joystick                (iii) Scanner                            (iv) MICR

    d) Which of the following was invented by Douglas Engelbart?
    (i) Computer Mouse    (ii) Keyboard               (iii) Scanner                             (iv) MICR

    e) How many digits are required to represent MICR codes?
    (i) 9                         (ii) 10                       (iii) 8                                       (iv) 7

    f) Which of the following is known as ‘Primary Memory’?
    (i) Main Memory          (ii) Secondary Memory           (iii) Sort Memory         (iv) None of these

    3. Answer the following questions:

    a) List the name of different keyboard layouts.

    Answer: Different keyboard layouts are QWERTY, QWERTZ, AZERTY and DVORAK.

    b) Explain the working of Bar Code Reader?

    Answer: Bar Code Reader emits a laser beam, which reflects with the bar code image. A light sensitive detector is present in the bar code reader which identifies and reads the barcode image. Once it is identified, the bar pattern is changed into numeric code which is processed inside the CPU.

    c) Justify the statement: RAM is also referred as volatile memory.

    Answer: RAM is also known as volatile memory because when a computer is got switched OFF or the power supply is interrupted, all the information present in it get lost.

    d) What is ‘Printer’? Explain the criteria on which it is classified?

    Answer: Printer is a common output device used to print documents, which contains data or information.
                 Printing mechanism is used to classify printers. Some printers print by striking the printer head on the paper, some print by forming image on the paper and some print by spraying of ink etc. Based on printing mechanism Printer can be broadly classified into two categories:
    (i) Impact Printer
                 (ii) Non-Impact Printer

    4. Write sort notes on:

    a) Joystick

    It is also a pointing device like Mouse except that a mouse pointer stops moving on the screen as soon as the user stops moving it, while joystick pointer continues to move in the direction towards with the joystick has been pointed.It is mostly used to play video games.

    b) Biometric Sensor

    It is a device which capture unique information from human body. It stores and compares to match the information with the web available database. This information can be fingerprint, iris pattern etc.

    c) Motherboard

    Answer: Motherboard is a large multi layered printed main circuit Board of a computer which contain slots, ports and sockets for attaching additional devices.

    d) Secondary Memory

    Memory which provides backup and storage of instructions or data that are permanent and can be retrieved back as and when required. It is also known as backup memory and has higher storage capacity.

    5. Expand the abbreviations:

    a) OMR          :      Optical Mark Reader

    b) OCR          :      Optical Character Reader

    c) MICR         :      Magnetic Ink Character Reader

    d) CAM          :      Computer aided manufacturing

    e) POST         :      Power on Self Test

    f) BIOS          :      Basic Input Output System

    g) BDA          :      Blu-ray Disk Association

    h) CAD          :      Computer Aided Design

    i) USB           :      Universal Serial Port

    j) DPI            :      Dot per Inch

    6. Suggest the answer in one word only:

    a) Which keyboard layout is widely used in Germany and Central Europe?

    Answer: QWERTZ.

    b) A group of 4 bits is known as:

    Answer: Nibble.

    c) Each plate of hard disk is known as:

    Answer: Platter.

    d) Diameter of a standard CD is:

    Answer: 120 mm.

    e) What is considered as the main circuit board of a computer?

    Answer: Motherboard.

    f) Which part of CPU is responsible for converting AC current into DC current?

    Answer: SMPS.

    g) Secondary memory is also known as:

    Answer: Backup Memory.

    7. Match the following with respect to their storage capacity:

    a) 1 TB


    b) 4 GB


    c) 32 GB


    d) 700 MB