Computer System

Mainframe computers are used by the Indian Railways to interact with the customers for the various online functions, like booking, cancellation, showing the current status and so on

Hybrid computer is a perfect combination of the Analog and Digital computer. It accepts analog signals, converts them to digital and processes them in the digital form.

Super computer is used in the National Research Centre which predicts natural calamities, like earthquake, tsunami, etc.

She can use a Tablet PC as it does not have a keyboard. It has a touch screen which is used to write directly on the screen rather than typing on a keyboard.

Arithmetic and Logical Unit

Read only memory is a part of internal memory.

Control unit is a component of CPU that controls the transfer of data and instructions among other units of computer.

Computers have zero IQ.

A microprocessor is a chip where a large number of circuit elements are integrated.

The speed of a CPU is determined by the number of instructions executed by it per second.

The speed of external memory is much slower than internal memory.

The three components of a CPU are Memory unit , Control unit and Arithmetic Logic Unit.

Primary memory is of two types, Random Access Memory and Read Only Memory.

The primary use of ROM is during the Booting process, which contains initial program to start a computer.

A computer compiles results using processing unit.

Cache memory is a special high speed memory, which stores frequently used instructions.

Two limitations of a computer are:

1. Limited Intelligence — As compared to human beings computers have limited IQ.
2. Dependence on Power — A computer is an electronic machine and thus its dependence on power makes it costly.

Two characteristics of a computer are:

1. Speed — A computer works at an amazing speed. The work which is done by a normal person in 2-3 hours can be done by a computer in a fraction of seconds.
2. Accuracy — A computer performs its task with great accuracy. It does not commit any mistakes. Errors occur only when the input is incorrect.

Computers facilitate research work in a very effective way by performing complex computations, which sometimes seem impossible for humans. Some of them are listed below:

1. The computations required for launching a new satellite into space.
2. Earthquake and Tsunami warnings are possible with the aid of computers.
3. Weather forecasting is done with the help of computers.
4. Impact of nuclear tests can be studied using computers.

Computers aid in the field of education in the following ways:

1. The multimedia rich computerized animations and videos help students to understand the concepts in a very simple and effective manner.
2. Virtual classrooms use video conferencing and online modules of study material for learning.
3. With the advent of e-learning, students can study according to their time schedule.
4. Online entrance exams at national and international level are being conducted with the help of computers.
5. The results of various education boards as well as entrance exams are available online.
6. Students can find information about various colleges through the Internet and can apply online for the desired courses.

Computers are used extensively in the field of sports.

1. The sports equipments used by athletes are first tested on computers.
2. There is a large number of computerized training equipment, which have inbuilt programs to train the sports person.
3. The training of athletes is done with the aid of computers.
4. Updation of scoreboards, recording speed of players, action replays, and printing and selling of tickets are some of the sports related activities which are also done with the help of computers.

Computers play a vital role in the field of military.

1. Computers are used in the design and development of high-tech weapons for defense where absolute accuracy is essential.
2. Computerized simulation exercises are very helpful in training the pilots.
3. Computers help in fighting terror and terrorists and their hideouts can be located anywhere in the world with high accuracy.
4. Computer technology enables governments around the world to successfully execute their plans through effective planning.

Government sector is making use of computer technology for official correspondence, budgeting, accounts, reporting, payroll, attendance, uploading of various schemes, forms, etc. Sectors like the census bureau, income tax, airlines, and railways, electricity boards, and telephone exchanges have benefitted greatly from the computer technology.

Computers play an important role in law enforcement. The traffic police uses speed cameras on traffic lights to monitor people for law violation. The police also uses computers to track the information of stolen automobiles and mobile phones in order to catch the criminals in less time.

Computers play a significant role in the field of engineering and manufacturing.

1. Architects and engineers take the aid of Computer Aided Design (CAD) and Computer Aided Engineering (CAE) for designing and manufacturing high quality products, like cars and planes.
2. Architects use computers for designing the layout of buildings and other civil engineering structures.
3. Advanced industrial robots are used to perform skillful and repetitive work.
4. Manufacturing with the support of robots and computers is called Computer Aided Manufacturing (CAM).

The input, process and output cycle for the withdrawal of 2000 rupees from my savings account, using an ATM card is as follows:

Input:

1. Insert ATM card — ATM card is inserted into the card reader slot on the ATM machine.
2. Enter PIN — Enter the PIN on the ATM's keypad.
3. Enter the amount to withdraw which in this case will be 2000.

Process:

1. Card authentication — The ATM machine processes the information on the card and authenticates the card.
2. PIN verification — The entered PIN is then validated to ensure it matches the one associated with the bank account.
3. Account verification — The ATM establishes a connection with the bank's computer system to verify the account details, balance, and transaction limits.
4. Funds availability check — The system checks if the account has sufficient funds to complete the withdrawal, else the transaction will be declined.
5. Dispense 2000 rupees — The ATM processes the withdrawal request, and the cash dispenser mechanism inside the ATM is activated to count and dispense 2000 rupees in the form of bank notes.
6. Update account balance — The bank's computer system updates the account balance to reflect the withdrawal.

Output:

1. Dispensed cash — The ATM dispenses the requested amount (2000 rupees) in banknotes through a secure slot.
2. Optional receipt — Optionally, the ATM may offer you a transaction receipt.
3. Transaction completion — The ATM returns your card, and the display usually shows a message indicating that the transaction is complete.

CPU is the main unit of a computer. It controls all the internal and external devices of a computer and performs arithmetic and logical operations. CPU is very small and is referred to as a microprocessor.

There are mainly three components of a CPU:

1. Memory Unit (MU) — The memory unit is the principal storage of the computer. It stores both data and instructions. Computer memory is classified into two categories:
   i. Internal Memory — It stores data and programs temporarily as long as they are being executed. It is very fast and expensive but has limited storage capacity. For example, RAM and ROM.
   ii. External memory — It stores data and programs permanently. For example, hard disk, CD/DVD etc.

2. Arithmetic and Logical Unit (ALU) — All the arithmetical and logical operations are performed through this unit. An arithmetical operation includes addition, subtraction, multiplication, division and logical operations include all types of comparisons.

3. Control Unit (CU) — This unit controls each and every part of the computer system along with the peripherals. It extracts the instructions from memory, decodes them and sends the necessary signals to ALU to perform the required operation. It is also called the central nervous system of a computer system as it manages all other units.

Microcomputers or personal computers use a microprocessor. They cost less and are very small in size. The most popular type of personal computers are the IBM PC and the Apple. The desktop computers that we use in our school labs, offices, homes etc. are micro-computers.

Two types of Microcomputers are:

1. Notebook Computer — It is an extremely light weight personal computer. It weighs around 5-6 pounds and is smaller in size than a laptop computer. A notebook does not have an integrated DVD drive like laptop. It generally has smaller memory than a laptop.
2. Tablet PC — A tablet PC looks similar to a laptop. A Tablet PC does not have a keyboard. It has a touch screen which is used to write directly on the screen rather than typing on a keyboard. Some common examples of Tablet PCs are Apple iPad, Samsung Galaxy Tab, etc.

The most powerful category of computers is super computers. These are the most powerful, the most expensive and the fastest computers in the world and are capable of processing trillions of instructions per second.

These computers are used by the government agencies, such as the Internal Revenue Service (IRS), the National Weather Service, and the National Defense Agency. These are also used in space exploration, large organizations, research laboratories, aerospace centers, and large industrial units.

The examples of Super computers are CRAY- 1, CRAY- 2, Control Data CYBER 205 IBM Road Runner, ETAA -10, etc.

Less storage capacity

Reason — A computer has great storage capacity.

Softcopy

Reason — The final output available to a user on the monitor is known as softcopy.

VDU

Reason — VDU (Visual Display Unit) is not a part of a CPU. Memory Unit (MU), Arithmetic Logic Unit (ALU) and Control Unit (CU) are parts of a CPU.

ALU

Reason — The component which is responsible for the control of all mathematical calculations and logical operations of a computer is called Arithmetic Logic Unit (ALU).

Processing

Reason — The process of converting unorganized data into meaningful information according to user's instructions is called Processing.

Data

Reason — Unorganized raw facts and figures given to a computer are collectively called Data.

Keyboard

Reason — The basic organization of a computer does not consist of Keyboard.

BIOS

Reason — ROM stores a set of instructions called BIOS (Basic Input Output System).

EPROM

Reason — The type of ROM which can have its contents erased by ultraviolet light is called EPROM (Erasable Programmable Read Only Memory).

Hard disk

Reason — A commonly used storage device is Hard disk.

Bit

Reason — The smallest unit of memory is Bit.

Cache

Reason — The special high speed memory which stores frequently used instructions so that a CPU can access them quickly is called Cache memory.

PROM

Reason — The memory which is programmed at the time of manufacturing and cannot be modified later is called Programmable Read Only Memory (PROM).

Binary form

Reason — The data is represented in binary form in digital computers.

Supercomputer

Reason — Supercomputer is not included in Microcomputers.

Think

Reason — A computer is not able to think. It only follows the instructions of its user.

Mhz

Reason — The speed of a CPU is measured in Mhz.

SMS

Reason — SMS is a quick and convenient way to send short messages.

A Computer System has three important parts-

1. Input Unit
2. Central Processing Unit
3. Output Unit

The three components of a CPU are:

1. Memory Unit (MU)
2. Arithmetic and Logical Unit (ALU)
3. Control Unit (CU)

The major strengths of a computer are:

1. Speed
2. Accuracy
3. Reliability
4. Storage Capacity
5. Versatility
6. Reduction in Manpower
7. Reduction in Paper work

The two types of primary memory are:

1. Random Access Memory (RAM)
2. Read Only Memory (ROM)

A blackboard is like a RAM that is constantly overwritten with the new data. A blackboard can be cleaned just as the data in the RAM is lost once the power is switched off.

An audio-video disk resembles a ROM. Once the songs are burned on a CD, the disc contents cannot be changed.

The speed of a processor is measured in Megahertz (MHz).

Hard disk is a storage device that is a part of secondary memory.

The smallest unit of memory is bit that can hold a single state - either 0 or 1.

The full form of BIOS is Basic Input/Output System.

Two processor (chip) manufacturing companies are Intel and AMD.

Three examples of input devices are keyboard, mouse and scanner.

Three examples of output devices are monitor, printer and speaker.

Five characteristics of a computer are:

1. Speed
2. Accuracy
3. Reliability
4. Storage Capacity
5. Versatility

False

Reason — Primary memory stores data and programs temporarily as long as they are being executed as primary memory has limited storage capacity.

True

Reason — MMS can be used for sending pictures and videos through mobile phones.

True

Reason — The functions of a computer are - Input, Process, Storage, and Output.

False

Reason — The Memory Unit stores data and instructions in memory storage devices.

True

Reason — A processor is a system board and is the most important hardware component of a computer.

True

Reason — Data required for processing is transferred from a secondary memory to a primary memory.

False

Reason — 1 Giga Byte is equal to 1024 Mega Byte.

True

Reason — RAM and ROM are also called Immediate Access Storage (IAS) as the CPU can access its data very fast as compared to data in the secondary memory.

True

Reason — Flash Memory is a specific type of EEPROM that can be erased and reprogrammed into big sections instead of one byte at a time.

False

Reason — Nibble is a group of 4 bits.