Session 2020-2021 Class : VII Subject : Computer Chapter : 1 (My Computer) Introduction: Computer is a machine that performs tasks or calculations according to a set of instructions or programs. It accepts data in the form of digitalized data and manipulates it for some result based on a program or sequence of instructions on how the data is to be processed. It is used in each and every aspect of human life such as home, education, science and research, medicine, publishing, etc. A computer is made up of two parts- hardware and software. Computer Hardware Software Input devices System Software Output devices Application Software Processing devices Storage devices 1. Fill in the blanks: a. Computer is a device that manipulates information and data. b. Device that can be seen and touched are called hardware. c. An input device sends data and instructions. d. LCD stands for Liquid Cristal Display. e. Computer’s storage unit is called secondary memory. 2. Tick the correct answer: a. Digital camera is an example of: (i) Input Device (ii) Output device (iii) Storage device (iv) None of these b. Flatbed scanner is known as: (i) Storage unit (ii) Memory unit (iii) Desktop scanner (iv) Plotter c. Light pen contains: (i) Dry cell (ii) Photo cell (iii) photon (iv) None of these d. Sound card is an example of: (i) Input device (ii) storage device (iii) output device (iv) processing device e. LCD projector is used to display: (i) An image (ii) A part of an image (iii) Both (i) and (ii) (iv) None of these f. CPU is known as: (i) Processing device (ii) Brain of computer (iii) Both (i) and (ii) (iv) None of these g. Memory unit is the ___________ of the computer. (i) Store room (ii) Power (iii) Input device (iv) output device h. Primary memory is called: (i) Secondary memory (ii) Main memory (iii) Cache memory (iv) None of these i. Plotter interprets: (i) Instructions (ii) Commands (iii) Both (i) and (ii) (iv) None of these Answer for tick the correct: a b c d e f g h i (i) (iv) (ii) (iii) (iii) (iii) (i) (ii) (iii) 3. Write ‘T’ for True and ‘F’ for False statements: a. Primary memory is called main memory. T b. A combination of 2 bit is called a nibble. F c. Bar code reader is usually used in shopping malls. T 4. Answer the following questions: Question a. What do you mean by hardware? Answer: A physical devices that can be seen and touched are called hardware. Computer has four types of devices. 1. Input devices: Keyboard, Mouse, Scanner, Microphone, web camera, etc. 2. Output devices: Monitor, Speaker, Printer, Plotter, Projector, etc. 3. Processing devices: CPU, etc. 4. Storage devices: Hard disk, Pen drive, CD/DVD, etc. Question b. What do you mean by Bar code reader? Answer: Bar code Reader is a device which is used to read the code from the products which are usually in the form of bars. It has a light sensitive detector which identifies the values of the bars on the products and converts them into numeric code. Question c. What is called memory? Explain briefly. Answer: Memory is a physical device which stores data or information on a temporary or permanent basis. There are two types of computer memory: (i) Primary memory: Primary memory is called the main memory of the computer. It stores data when the computer is in operation. RAM (Random Access Memory) and ROM (Read Only Memory) are two types of primary memory. (ii) Secondary memory: Secondary memory provides backup storage for data and instructions. It stores the data permanently unless it cannot be erased. It is the slowest and cheapest form of memory. It is also called non – volatile memory. CD-DVD, Pen drive, Hard disk are some secondary memories. Question d. What do you mean by Plotter? Explain briefly. Answer: Plotter is a printing device that interprets commands from a computer to make line draw on paper such as construction of maps or engineering drawing. It can draw continuous point-to-point lines from vector graphic file or commands. Plotters consist of three types: (i) Drum plotter (ii) Flatbed plotter (iii) Inkjet plotter Question e. What do you mean by software? Answer: Software is a collection of instructions and code installed into the computer. Software cannot be touched like hardware but are stored only on storage mediums. Software operates the hardware. Software is two types- System software and Application software. 5. Give the full forms of the following: (i) RAM Random Access Memory (ii) ROM Read Only Memory (iv) DVD Digital Versatile Disk (v) ALU Arithmetic Logic Unit (vi) CPU Central Processing Unit (vii) CU Control Unit (viii) HDD Hard Disk Drive (ix) CD Compact Disk 6. Define the following term: (i) System Software: System software is a collection of program that supports the computer operations and allows us to communicate with the computer. For example: Operating System, Windows, MAC OS, Linux, etc. (ii) Application software: Application software is a program which helps the user to perform specific tasks such as word processing, spreadsheets, graphics, desktop publishing, etc. for example Microsoft Office, Corel Draw, etc. 7. Draw the following diagrams: a. MS Office logo page. b. Linux logo page c. Pen drive d. Light pen e. Hard Disk Complete all the exercises and diagrams in your note book .