Chapter :- 1 Computer System
Summary :-
A computer is an electronic device which converts raw data into useful information as per the user's instructions.
A computer works on the principle of Input Process -> Output, i.e. IPO cycle.
Raw facts given as input to the computer are called data whereas the processed form of data is known as information
CPU is the main data processing unit also known as the brain of the computer.
ALU (Arithmetic and Logical Unit) and CU (Control Unit) are the two main components of cru.
Main memory of the computer is like a warehouse in which processed and unprocessed information are stored.
High data processing speed, accuracy, storage, diligence and versatility are the advantages of this machine.
Zero IQ, no intelligence and no learning capability are the limitations of a computer.
Some of the major areas of computer applications are: Business, Research, Education, Communication, Defence, Healthcare, Entertainment, Personal Use, Banking, Multimedia, Transportation and Simulation.
SOLVED QUESTIONS
Q1. Define a computer?
Ans. A computer is an electronic device which processes user data as per the instructions to produce the desired output.
Q2. What is the difference between Data and Information?
Ans.The term data is used for the raw facts which is processed by the computer whereas information is the processed form of 'data', i.e. the output produced by the computer.
Q3. What are the four major functions of the computer system?
Ans. Input, output, storage and processing.
Q4. What are the two components of Central Processing Unit (CPU)?
Ans. Arithmetic and Logical Unit (ALU)
Control Unit (CU)
Q 5. What are the two main characteristics of a computers?
Ans. The two main characteristics of a computer system are: Speed and Accuracy.
Q6. What do you understand by diligence as a characteristic of computer?
Ans. Diligence refers to the continuous working of the computer system for long hours without getting tired
Q.7 Q7. What are the limitations of computer system? Ans. • Zero IQ
• Lack of decision making power
• No learning power
Q8. How can computers be used in the field of communication?
Ans. Computers are most effectively used for communication with the help of Internet.
E-mails can be sent electronically to their destination in no time.
Videoconferencing allows to see the distant person while talking to him.
Instant messaging applications can be used to exchange text messages in real time
Tick the correct answer.
1.The word 'Computer' is derived from Latin word
Compute Compare Computare None of these
2.The four basic functions of computer system are
Input, Process, Output and Storage Input, Process, Output and Project
Input, Compare, Output and Storage All of these
3.The term____________ is used for the raw facts which need to be processed by the computer.
Data Information Storage Process
4._________memory is used to hold the processed results permanently for the later use.
Primary External Main Secondary
5.With the help of ____________ data and instruction are entered in the computer systems.
Input Unit Output Unit Control Unit Arithmetic Logical Unit
6.___________ is also known as the brain of the computer.
CPU ALU CU MU
7.The information stored in the___________ form inside the computer is converted into the user readable form before it appears on the output unit.
Binary Bit Both of these None of these
8. Among the following devices___________is an output device.
VDU Keyboard Mouse Joystick
9.The information represented in the form of text, audio, images, animation, video and interactiveco is called _________
Graphics Multimedia Media None of these
10. The full form of GPS is
Global Positioning System Global Piloting System
Globe Positioning System Global Positioning Simulation
B. Write T for True and F for False statement.
1. A computer can work with 100% accuracy but has no intelligence of its own. :- True
2. Data is the processed form of information produced by the computer. :- False
3. Main memory of the computer directly interacts with the CPU. :- True
4. Computer possesses better learning power as compared to human being :- False .
5. The function of a computer are: input, process, storage and output. :- False
6. The processing speed of the computer is very high.:- True
7. A computer is unable to store a large amount of information.:- True
8. In a computer, all types of data processing are carried out by the ALU.:-False
9. The working principle of a computer is IPO. :- True
10. Output Unit converts the data into the binary form and stores it into the main memory of the computer. :- False
C. Fill in the blanks.
1. A computer is an electronic device which processes the user's data to produce useful Output.
2. CPU component, which performs arithmetic and logical operations is known as ALU
3.High speed and Accuracy are the two major advantages of computer system.
4. Data in the memory unit are stored in the form of binary digits.
5. A computer can take decision with the help of input given by the user.
6. Main memory of the computer directly interacts with the CPU
7. Once the data is processed, the results are stored back into the of the system which is received by the users on the
8. The speed of a computer is measured in Megahertz and Gigahertz.
Answer in short.
1. What is a computer?
Ans :- Computer is an electronic device which take input for the user process it and gives us output.
2. What is the difference between Data and Information?
Ans :- Raw facts given as input to the computer are called data whereas the processed form of data is known as information.
3. What are the four functions of the computer system?
Ans :- 1. Input: Accepts data and instructions.
2. Processing: Manipulates data as per instructions,
3. Output: Produces desired output/information.
4. Storage: Stores data, instructions and information.
4. Which component of the CPU performs all types of processing jobs?
Ans :- Control Unit.
5. In which unit of the computer system, processed and unprocessed data are stored?
Ans :- Storage Unit.
6. In which form, data in the memory unit are stored?
Ans:-Binary form
7. What do you understand by the term 'Processing'?
Ans:- Manipulates data as per the instruction.
8. Write any two uses of a computer in the field of defence.
Ans :- Defence Most of the sophisticated weapon systems and guided missile systems are controlled by the computer nowadays.
Crucial information is encryp sent to various destinations using computers.
9. What do you understand by IPO cycle?
Ans :- Input Process Output
10. What is the difference between the working of ALU and CU?
Ans :-
ALU is stand for Arithmetic Logical Unit | CU is stand for Control Unit
ALU also deals with manipulation of the data and work according to the instructions of the control unit. | Control Unit provides instructions to the arithmetic logical unit and coordinates according to the nature of the data provided and nature of work to be performed.
11. Write any two important characteristics of a computer.
Ans :- High Storage Capacity: A computer can store a large amount of information. The stored information can be retrieved very quickly when needed without failure.
Reduction in Paper Work: The use of computers leads to reduction in paper work and speeds up the
process.
12. What are the limitations of a computer system?
Ans :-Zero IQ:
No Learning Power
Answer in detail.
1. Explain the working of a computer system with the help of its data flow diagram
Ans :- Although a computer is based on a complex technology, its working principle is very simple. Just like many day-to-day tasks we do in three stages, called input, process and output, computer also follows the same cycle to produce the desired output, called Input-→ Process -> Output or in short, IPO cycle.
1. Input: Accepts data and instructions.
2. Processing: Manipulates data as per instructions.
3. Output: Produces desired output/information.
4. Storage: Stores data, instructions and information.
2. What are the major characteristics of a computer system? Explain.
Ans:- 1. High Speed: The processing speed of the computer is very high as it can process millions of instructions per second. The speed of a computer is measured in Megahertz (MHz) and Gigahertz (GHz). It means that a job, which can take days if performed manually, can be finished within a few seconds in the computer.
2. Accuracy: In addition to its high speed, the accuracy of this machine is consistently high. If the data and instructions given by the user are error free and the hardware does not malfunction, it always gives 100% accurate results.
3. Diligence: Computer, being a machine does not suffer from tiredness or lack of concentration and can work continuously for hours without making any mistake. It can carry out each instruction precisely with same accuracy and speed everytime. Thus, it is more reliable than a human being.
4.High Storage Capacity: A computer can store a large amount of information. The stored information can
be retrieved very quickly when needed without failure.
5. Reduction in Paper Work: The use of computers leads to reduction in paper work and speeds up the process.
3. Explore the various applications of computers a in the field of education.
Ans :- Computers are effectively used as teaching aids in classrooms. Nowadays, with the increasing use of Internet, students can undergo online courses offered by the various universities while sitting at their homes. They can attend the online lectures and can speak to their teachers to get the response to their queries. These virtual classrooms are the future of education.
4. Write a short note on the working principle of a computer.
Ans:- Same as Answer number 1
5. Define the following:
a. Input Unit :- Data and instruction are entered in the computer systems with the help of input unit, which act like a link between user and computer. Computer uses different types of input units, like, keyboard, mouse, scanner, microphone, etc. depending on the type of data or the format of instructions to be given to it.
b. Output Unit :-Once the data is processed, the users receive the results on an output unit. The information stored in the computer is converted into the user readable form before it appears on the output unit. commonly used output devices are monitor, printer, speakers, plotter, etc.
c. Arithmetic Logic Unit :- It mainly comprises of two units ALU (Arithmetic and Logical Unit). All types of data processing are carried out by the ALU
d. Control Unit :- CU (Control Unit) whereas CU helps to control the flow of data in the system one part to another
e. Primary Memory :-Main memory of the computer is also known as Primary memory as it stores everything like data, instruction and information in the binary form which is directly understood by the CPU or processing unit.
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