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Sunday, January 25, 2015

Types of Computer

On the basis of working principle there are three types of computers.

a)Analog Computer
An analog computer (spelt analogue in British English) is a form of computer that uses continuous
physical phenomena such as electrical, mechanical or hydraulic quantities to model the problem being solved.
1. Thermometer
2. Speedometer
3. Petrol Pump Indicator
4. Multi meter

b) Digital Computer
Acomputer that performs calculations and logical operations with quantities represented as digits, usually in the binary number system.

c) Hybrid Computer (Analog + Digital)
A combination of computers those are capable of inputting and outputting in both digital and analog
signals. A hybrid computer system setup offers a cost effective method of performing complex simulations.

On the basis of Size..
a)Super Computer 
It is the fastest computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations.
For example, weather forecasting requires a supercomputer. Other uses of supercomputers
include animated graphics, fluid dynamic calculations and nuclear energy research and petroleum
exploration.
The major difference between a supercomputer and a mainframe is that a supercomputer channels
all its power into executing a few programs as fast as possible, whereas a mainframe uses itspower to execute many programs concurrently.

b)Mainframe Computer
A very large and expensive computer capable of supporting hundreds and even thousands of users
simultaneously. In the hierarchy that starts with a simple microprocessor (Eg: in watches) at the
bottom and moves to supercomputers at the top, mainframes are just below supercomputers. In
some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program
faster than a mainframe.

c) Mini Computer
In size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the
distinction between small minicomputers and workstations. But in general, a minicomputer is a
multiprocessing system capable of supporting from 4 to about 200
users simultaneously.

d)Micro Computer
i. Desktop Computer: A personal or micro-mini computer sufficient to fit on a desk.
ii. Laptop Computer: A portable computer complete with an integrated screen and keyboard. It is
generally smaller in size than a desktop computer and larger than
a notebook computer.
iii. Palmtop Computer/ Digital Diary/ Notebook / PDAs:Ahandsized computer. Palmtops have no keyboard but the screen serves both as an input and output device.

e)Workstations
It is a terminal or desktop computer in a network. In this context, workstation is just a generic term
for a user's machine (client machine) in contrast to a "server" or "mainframe."

Major brands of the computer:
a) IBM/ IBM Compatible Computers
b) Apple/ Macintosh.

Monday, December 22, 2014

COMPUTER AWARENESS PRACTICE QUESTIONS

1. UNIVAC stands for?
A) Universal Automatic Computer
B) Universal Array Computer
C) Unique Automatic Computer
D) Unvalued Automatic Computer
E) None of these

2. The basic operation performed by a computer is ____
A) Arithmetic operation
B) Logical operation
C) Storage and relative
D) All the above
E) None of these

3. The two major types of computer chips are:
A) External memory chip
B) Primary memory chip
C) Microprocessor chip
D) Both b and c
E) Both a and b

4. Microprocessors as switching devices are for which generation computers?
A) First Generation
B) Second Generation
C) Third Generation
D) Fourth Generation
E) None of the above

5. What is the main difference between a mainframe and a super computer?
A) Super computer is much larger than mainframe computers
B) Super computers are much smaller than mainframe computers
C) Super computers are focused to execute few programs as fast as possible while mainframe
uses its power to execute as many programs concurrently
D) Super computers are focused to execute as many programs as possible while mainframe
uses its power to execute few programs as fast as possible
E) None of the above

6. ASCII and EBCDIC are the popular character coding systems. What does EBCDIC stand for?
A) Extended Binary Coded Decimal Interchange Code
B) Extended Bit Code Decimal Interchange Code
C) Extended Bit Case Decimal Interchange Code
D) Extended Binary Case Decimal Interchange Code
E) None of the above

7. The brain of any computer system is ___
A) ALU
B) Memory
C) CPU
D) Control unit
E) Keyboard

8. Storage capacity of magnetic disk depends on ___
A) tracks per inch of surface
B) bits per inch of tracks
C) disk pack in disk surface
D) All of the above
E) Only A and B

9. The two kinds of main memory are:
A) Primary and Secondary
B) Random and Sequential
C) ROM and RAM
D) All of the above
E) None of these

10. A storage area used to store data to compensate for the difference in speed at which the different units can handle data is ___
A) Memory
B) Buffer
C) Accumulator
D) Address
E) None of these

11. Computer is free from tiresome and boardroom. We call it ___
A) accuracy
B) reliability
C) diligence
D) versatility
E) programmability

12. Integrated Circuits (ICs) are related to which generation of computers?
A) First generation
B) Second generation
C) Third generation
D) Fourth generation
E) Fifth generation

13. CD-ROM is a ___
A) Semiconductor memory
B) Memory register
C) Magnetic memory
D) All of the above
E) None of the above

14. A hybrid computer:
A) Resembles digital computer
B) Resembles analogue computer
C) Resembles both a digital and analogue computer
D) Converts digital to analog
E) None of the above

15. Which type of computers uses the 8-bit code called EBCDIC?
A) Mini computers
B) Micro computers
C) Mainframe computers
D) Super computer
E) None of these

16. The ALU of a computer responds to the commands coming from:
A) Primary memory
B) Control section
C) External memory
D) Cache memory
E) None of these

17. Chief component of first generation computer was ___
A) Transistors
B) Vacuum Tubes and Valves
C) Integrated Circuits
D) All of the above
E) None of the above

18. To produce high quality graphics (hardcopy) in color, you would want to use a/an ___
A) RGB monitors
B) Plotter
C) Ink-jet printer
D) Laser printer
E) None of these

19. What are the stages in the compilation process?
A) Feasibility study, system design and testing
B) Implementation and documentation
C) Lexical Analysis, syntax analysis, and code generation
D) Both A and B
E) None of the above

20. Which of the following IC was used in third generation of computers?
A) SSI
B) MSI
C) LSI
D) Both a and b
E) None of these

ANSWERS:
1) A 2) D 3) D 4) D 5) C 6) A 7) C 8) D 9) C 10) B
11) C 12) C 13) E 14) C 15) C 16) B 17) B 18) B 19) C 20) D