Types of Computer

Types of Computer:


Types_of_Computer


v    On the basis of Working Principle:

a)            Analog Computer:An analog computer is a form of computer that uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved.

Example: Thermometer, Speedometer, Petrol pump indicator, Multimeter 

 

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

Example: Personal Computer, Laptop, Desktop, Mobile Phone etc.

 

Digital_computer 

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. The instruments used in medical science lies in this category.

Example:

Hybrid_computer

v On the basis of Size

   a. Super Computer: Some specialized applications requires immense power to calculate mathematical operations and to serve that purpose we need Supercomputers, which are very fast and expensive computers. PARAM is an example of supercomputer made in India. Supercomputers are capable to execute single operation faster than the other like Mainframe Computer.


Applications of Supercomputer are as follows:

1.   Weather forecasting

2.   Graphics Animation

3.   Nuclear Research etc.

Supercomputer

b. Mainframe Computer: Mainframe Computers are more expensive and larger in capacity to support hundreds or even thousands of user programs at a time whereas supercomputers can execute single operation faster than Mainframe Computer.

Main-frame-computer

c. Mini Computer: Minicomputer stands between workstation and mainframe computer. Mini Computer is a mid-size and less expensive than mainframe computer, capable to support 2 to 300 users at a time. For example- Server is an example of minicomputer.

Mini-computer

d. Micro Computer: Personal Computers (PC’s) are examples of Micro Computer, which is capable to support only one user at a time and much cheaper to afford easily for personal work. Example of such computers are as follows:

Micro-Computer

i. Desktop Computer: Is a personal computer much smaller to fit into a desk.

ii. Laptop Computer: Is a portable computer with integrated Screen and Keyboard.

 iii. Mobile Phones/Palmtop Computer/ Notebook /PDAs: These are the palm size compute with onscreen keyboard.

       e. Workstations: Workstation is a terminal or Desktop Computer in a Client-Server Network, which are  basically used for software development, desktop publishing. It uses single operating system with large size RAM and storage devices capable to store user’s data and application software.


Workstation-computer


Language processor/ Language Translator

Language processor/ Language Translator

Language processor/Language Translator

Computer hardware can only understand machine level languages or instructions. But, in most cases we use only High level languages. So it is the necessity to convert the HLL’s into its corresponding machine level language. There are mainly three types of language processor are currently in use, such as-

v  Compiler: Compiler is a language translator, which converts the high level language into machine level language by compiling the whole program at once. So, it takes less time to compile the whole program.

v  Interpreter: Interpreter is also a language translator, which converts the high level language into machine level language by interpreting line by line. When it gets an error it stops interpreting and report user about the error. It resumed its interpretation until the error being corrected by the user. That’s why it takes more time to compile a program than compiler.

v  Assembler: Assembler is also a language translator, which converts assembly level language into machine level language.

Computer Software

Computer Software

   Computer Software: 

  To perform various tasks computer needs to have specific computer software. In simple term computer       software is nothing but a computer program, which is a collection of instructions given to a computer       system to perform the specified task. Depending on the requirement computer software can be categories    into following category such as:

v      System software: For Example- Operating System Software 

                                   DOS, Windows XP, Windows Vista, Unix/Linux, MAC/OS X etc. 

v     Application software:  For Example- 

                                     Ms. Office 2003, Ms. Office 2007, 

                                     Macromedia   (Dreamweaver, Flash), Adobe (Page Maker, Photoshop) 

v      Utility Software:  For Example- Device Driver.


Nielit Previous year question paper & Solution

Nielit Previous year question paper & Solution
      
Nielit Previous year question paper & Solution, 2018

       Q. Evaluation of the given post fix expression 10 10 + 60 6/*8-
         Ans:    10 10 + 60 6/*8- (Post fix expression)
ð  10 + 10   60 / 6 – 8  ( Infix expression)
ð  ((10 + (  ( 10   60)  / 6 ) ) – 8 )  (well parenthesized)
ð  ((10 +  600  / 6 ) ) – 8 )  
ð  (10 + 100 ) – 8 )  
ð  (110 – 8 )  
ð  102
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     Q. ( A+C’ ) ( B’+C’ ) Simplifies to-
      Ans: ( A+C’ ) ( B’+C’ )
ð  AB’ + AC’ + B’C’ + C’C      As we know C’C’ = C’]
ð  AB’ + AC’ + B’C’ + C’
ð  AB’ + AC’ + C’ (B’+1)        As we know  B’ +1= 1]
ð  AB’ + AC’ + C’
ð  AB’ + C’ ( A’ + 1 )             As we know  A’ +1= 1]
ð  AB’ + C’

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Q. ______________ is NOT a part of the ACID properties.

(A) Inconsistency

(B) Consistency

(C) Atomicity

(D) Isolation

Ans: Inconsistency

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Q. Identify the true statement from the given statements.

(1)  FIFO is non-preemptive

(2)  Round Robin is non-preemptive.

(3)  Multilevel Queue Scheduling is non-preemptive.

Ans: (1) FIFO is non-preemptive

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Q. Dijkstra’s algorithm is based on:

    (A) Greedy Approach 

   (B) Dynamic Programming

    (C)  Backtracking Paradigm

   (D) Divide and conquer paradigm

Explanation: Dijkstra’s algorithm is based on(A) Greedy Approach

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Q.  Identify the total number of tokens in the given statement:

      printf ( “ A % B = ” , &I ) ;

       (A) 7

    (B) 8

       (C)  9

    (D) 13

Explanation: 

1. printf 

2. (

3. “A%B=”

4. ,

5.  &

6. I

7.  )

8.  ;

Option: (B) 8 is the total number of tokens in the given statement

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Q. Identify the true statement from the given statements.

1.   HTTP may use different TCP connection for different objects of a web page if non-persistent connections are used.

2.   FTP uses two TCP connections, one for data and another for control.

3.   TELNET and FTP can only use TWO connection at a time.

      (A) 1

     (B) 1 and 2

      (C)  2 and 3

     (D) 1, 2 and 3

Ans:  Option: (B) 1 and 2 is the correct one.

Explanation: 

HTTP may use different TCP connection for different objects of a webpage if non-persistent connections are used, because client and server need to establish one new TCP connection for each object of a webpage. But, in case of persistent connection only one TCP connection can serve the purpose.

FTP uses two TCP connections, port 20 used to sand data and port number 21 used for control.

Telnet uses port number 23 as a TCP connection.

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Q. _________________ number of queues are required to implement a stack.

     (A) 1

     (B) 2

     (C)  3

     (D) 4

Ans: Option (B) 2 is the correct one.

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Q. ____________________ IP address can be used in WAN.

     (A) 265.0.0.1

    (B) 172.16.0.10

     (C) 15.1.5.6

    (D) 127.256.0.1

   Explanation: (B) 172.16.0.10 IP address can be used in WAN, (A) 265.0.0.1 and (D) 127.256.0.1 are not valid IP addresses to be used in IPv4, because an IP address in IPv4 can be represented in 32bit binary number or 4 byte, which can be further represented in doted decimal number where dot (.) being placed after each 8bit, so with 8 bit, 28=256 or 0 to 255 are the range of the IP address. In (A) 265.0.0.1 and (D) 127.256.0.1, 256 is invalid for any IP address of IPv4 addressing. And (C) 15.1.5.6 is being used for private addresses only.

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Q. ____________transport layer protocol is used to support electronic mail.

     (A) SNMP

     (B) IP

     (C)  SMTP

     (D) TCP

Explanation: Option (D) TCP is correct one, as SMTP is an Application Layer protocol, which uses TCP as transport layer protocol to support electronic mail.
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Q. ______________is used to convert from recursive to iterative implementation of an algorithm.

     (A) Array

     (B) Tree

     (C)  Stack

     (D) Queue

Explanation: Option (C) Stack is the correct one. Recursive function calls works in Last In Fast Out paradigm. So, stack is the only data structure, which supports LIFO paradigm from the above options.
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Q. _________________ pairs of traversals is not sufficient to build a binary tree.

    (A) Preorder and Inorder

    (B) Postorder and Inorder

    (C)  Postorder and Preorder

    (D) None of the above

Explanation: (C) Postorder and Preorder pairs of traversals is not sufficient to build a binary tree.

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Q. Among all given option, __________________ must reside in the main memory.

    (A) Assembler

    (B) Compiler

    (C)  Linker

    (D) Loader

Explanation: Option:(D) Loader is the correct one. Loader resides in MAIN memory to load the object program into main memory from the secondary memory, when executing any program.

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Q. Time to Live (TTL) field in the IP datagram is used _____________

    (A) to optimize throughput

    (B) to prevent packet looping

    (C)  to reduce delays

    (D) to prioritize packets

Explanation: Option: (B) to prevent packet looping is the correct one.

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Q. Maximum number of superkeys for the relation schema 

    R (X, Y, Z, W) with X as the key is:

     (A) 6

    (B) 8

     (C)  9

    (D) 12

Ans: (B) 8

Explanation:

   Maximum number of superkeys possible for any relations with n attributes can be express with the following expression: 2^(n-1)

    Here, n= 4

So, the possible superkeys is =2^(4-1)= 2^3=8

Example: X, XY, XZ, XW,XYZ,XYW,XWZ, XYZW

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Q. If the period of a signal is 100ms. Then its frequency in Hertz is ___________

     (A) 10

     (B) 100

     (C)  1000

     (D) 10000

    Explanation: As we know Time period and Frequency has inverse relation with each other. So, as the time increases frequency goes down and when the time period decreases the frequencies goes up. For example:

     Time

     Hertz

     1Second

     1 Hertz

     1Milisecond

     1 Kilo  Hertz

     1Microsecond

     1 Mega Hertz

     1Nenosecond

     1 Giga Hertz

Similarly:

     Time

   Hertz

     1        Millisecond

    1     Kilo  Hertz

     10      Millisecond

    100 Hertz

     100    Millisecond

    10   Hertz

     1000Millisecond

    1     Hertz

So, when the period of a signal is 100ms, its frequency in Hertz becomes 10 Hz.

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