CBSE Computer-Science Class-VII (Solved Exercise-1):

Computer Science

Class-VII

Chapter-1 Computer Fundamentals

Section-1

A. Answer these questions orally:

1. What do you know about IPO cycle?

Answer: IPO stands for Input-Process-Output. The computer system works on the principle of IPO cycle.

Input- Computer receive input in the form of instruction.

Process- Computer process the input data.

Output- Computer display the processed data.

2. How does light pen work?

Answer: The tip of the light pen has a light-sensitive detector. When the tip is in contact with the screen, it detects the light from the screen. The computer then identifies the location of the pen on the screen and works accordingly.

3. Name the main parts of CPU.

Answer: Main part of CPU:

1. Control Unit(CU)

2. Arithmetic Logic Unit (ALU)

3. Memory Unit (MU)

4. What are language processor?

Answer: Computer understands only machine language. Language processor have the responsibility of converting programming languages like assembly language and high level languages into machine understandable form.

B. Tick the correct option:

1. RAM is the ______ memory.

a. volatile               b. temporary             c. read/write           d. all are correct

Answer: c. read/write

2. 1 nibble is equal to:

a. 4 bits                   b. 8 bits                    c. 12 bits                 d. 16 bits

Answer: 4 bits

3. _______ refers to the programs that are stored in computers.

a. Hardware            b. Software              c. Memory              d. RAM

Answer: Software

Section-2

A. Fill in the blanks:

1. The keyboard helps you to ________ faster.

Answer: Work

2. The tip of the light pen has a ______ detector.

Answer: Light sensitive

3. Laser printers use _______ to produce high quality printouts.

Answer: Laser beams

B. State True or False:

1. The instructions stored in ROM cannot be over-written.

Answer: T

2. 1024 MB is equal to 1 TB.

Answer: F

3. Hardware are the intangible components of computer.

Answer: F

C. Answer the following questions:

1. Why is scanner regarded as an input device?

Answer: A scanner is an input device that copies written documents, photographs and pictures and transfers them to the computer directly.

2. Distinguish between:

a. Input and Output devices                b. RAM and ROM

c. Primary and Secondary memory     d. Hardware and software.

Answer: 

a. Difference between input and output devices are:

Input device is used to give instructions to the computer.

Output device is used to take result from computer.

b. RAM stands for Random Access Memory. It is a temporary memory.

ROM stand for Read only Memory. It is a permanent memory.

c. Primary memory is also called internal memory. They are already installed in computer system.

Secondary memory is also called external memory. These memories can be attached to the computer externally.

d.  Hardware - Physical parts of computer are called hardware.

 Software- Set of programs is called software.

 

3. What is an operating system? Write the tasks of an operating system.

Answer: The operating system is a set of programs which allows you to communicate easily with the computer. It a acts as an interface between the user and the hardware.

Task of an operating system:

1. Recognizing input from the keyboard.

2. Sending output to the display screen.

3. Keeping track of files and directories on the disk.

4. Controlling peripheral drives like the floppy and CD drive and programs.