Programmer at Bangladesh National Parliament Secretaritat-2014

Programmer at Bangladesh National Parliament Secretaritat-2014

Q-1.What is Universal Logic gate ? Write the truth table of its .

Ans:  A universal gate is a gate which can implement any Boolean function without need to use any other gate type. NAND and NOR gates are widely known to be universal logic gates, meaning that any other logic gate be made from NAND or NOR gates.

Q-2.Write the difference between RAM and ROM

Ans:

Differences between RAM and ROM are :

RAM	ROM
1. Random Access Memory	1. Read only Memory
2. Volatile(maintains its data while the device is powered)	2. Non-Volatile (does not lose content when power is lost)
3. Stores information temporary	3. Stores information permanently
4. Requires flow of electricity to retain data	4. Does not require flow of electricity to retain data
5. Large size with higher capacity	5. Small size with less capacity
6. Used for both read and write	6. Used only for reading
7. Costlier	7. Cheaper than RAM
8. Very fast but uses a lot of power	8. Fast but uses very little power
9. Used in CPU cache, primary memory	9. Used in firmware, microcontrollers

Q-3.Define access time,seek time and transfer time .

Ans:Access time:The time required for a computer program or device to locate and retrieve, or to write and store, a piece of data.

Seek time: Seek time  is the time taken for a hard disk controller to locate a specific piece of stored data. 

Transfer time:The time it takes to transmit or move data from one place to another. It is the time interval between starting the transfer and the completion of the transfer.

 

Q-4.What is data structure ? Give the example of linear data structure

Ans: A data structure is a particular way of organizing data in a computer so that it can be used effectively.

Data structure where data elements are arranged sequentially or linearly where the elements are attached to its previous and next adjacent in what is called a linear data structure

Example:

·         Array

·         Linked List

·         Stack

·         Queueetc

Q-5.Differentiate between array and linked list

Ans:

BASIS FOR COMPARISON	ARRAY	LINKED LIST
Basic	It is a consistent set of a fixed number of data items.	It is an ordered set comprising a variable number of data items.
Size	Specified during declaration.	No need to specify; grow and shrink during execution.
Storage Allocation	Element location is allocated during compile time.	Element position is assigned during run time.
Order of the elements	Stored consecutively	Stored randomly
Accessing the element	Direct or randomly accessed, i.e., Specify the array index or subscript.	Sequentially accessed, i.e., Traverse starting from the first node in the list by the pointer.
Insertion and deletion of element	Slow relatively as shifting is required.	Easier, fast and efficient.
Searching	Binary search and linear search	linear search

Q-6.What is binary search Tree ? Draw a BST using following data :18,22,7,23,25 and 37

Ans:

A Binary Search Tree (BST) is a tree in which all the nodes follow the below-mentioned properties −

·        The left sub-tree of a node has a key less than or equal to its parent node's key.

·        The right sub-tree of a node has a key greater than to its parent node's key.

Q-7.Whst is flowchart ? Draw a flowchart of finding out the biggest number between two numbers.

Ans: A flowchart is the graphical or pictorial representation of an algorithm with the help of different symbols, shapes and arrows in order to demonstrate a process or a program.

Q-8.Write a program to check that a number is prime or not.

Ans:

#include<stdio.h>

#include<conio.h>

int main()

{

int n, f=1,i;

printf("Enter a Number: ");

scanf("%d",&n);

int limit= sqrt(n);

for(i=2;i<=limit; i++)

    {

            if(n%i==0)

            {

                        f=0;

                        break;

                        }

            }

           

            if(f==0)

printf("Not prime");

else

printf(" prime");

            getch();

            return 0;

}

Q-9.What is network topology ? Describe about 2 topologies.

See-Sub-AME at Department of Immigration & Passport-2014

Q-10.Differetiate between IPV4 aND IPv6

Ans:

IPV4	IPv6
IPv4 has 32-bit address length	IPv6 has 128-bit address length
Address representation of IPv4 in decimal	Address Representation of IPv6 is in hexadecimal
It Supports Manual and DHCP address configuration	It supports Auto and renumbering address configuration
In IPv4 end to end connection integrity is Unachievable	In IPv6 end to end connection integrity is Achievable
It can generate 4.29×109 address space	Address space of IPv6 is quite large it can produce 3.4×1038 address space
Security feature is dependent on application	PSEC is inbuilt security feature in the IPv6 protocol
In IPv4 checksumfield is available	In IPv6 checksumfield is not available
IPv4 has header of 20-60 bytes.	IPv6 has header of 40 bytes fixed

Q-11.Describe about twisted pair, coaxial and fiber optic cable

Ans:

Twisted Pair Cables

A twisted pair means that the cable is designed with two independent insulated wires wrapped around each other. This method is used as a means to reduce interference from the electromagnetic spectrum, which allows the network devices to run smoother with less noise from outside sources (noise can come from multiple sources, such as power lines). There are two different types of twisted pair cables, shielded twisted pair (STP) and unshielded twisted pair (UTP):

• STP cables have an extra covering that acts as a ground to the phone cable to carry data at faster rates.
  
  
• UTP cables don't have this extra covering, but that's not to say they are lousy networking cables. In fact, UTP cables are the most popular and commonly used cables today.

Coaxial cable:Coaxial cable is used to transmit electrical energy from one location to another. It is used in computer networks and by cable service providers.

There are two types of coaxial cables which are widely used:

1. 50-ohm cable( Used for digital transmission)

2. 70-ohm cable(Used for analog transmission)

Coaxial cables have layers of electrical conductors and insulating materials. The central conductor layer is a thin copper conducting wire. Next, we have the dielectric layer made up of insulation material. A shield layer of copper mesh is around the dielectric layer. All these layers are wrapped in an insulation jacket.

Advantages of a coaxial cable:

1. Inexpensive

2. Flexible

3. High-frequency range

4. High-bandwidth as compared to twisted cables

5. Immune to noise due to better shielding

6. Low error rate

7. Can be used for analog transmission as well as for digital transmission

8. High transfer rate

Disadvantages of a coaxial cable:

1. Easily breakable

2. Difficult to install and maintain due to copper thickness

3. A single cable is used for transmission, in case of any damage to the cable an entire network can go down.

Fiber-optic cable:A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed.

Advantages of fiber optic cable

·         Optical fiber cable supports extremely high bandwidth and speed.

·         It offers low power loss

·         It is immune to electromagnetic interference

·         Optical fibers have a long lifespan

·         It is thinner and light weighted

·         Optic fibers are more flexible when compared to copper fibers of the same diameter

Disadvantages

·         It is more difficult to install

·         Fiber optic cable is small and compact cables and it is highly susceptible to becoming cut or damaged during installation and construction activities.

Q-12.What is the relational database? write 2 names of database server.

Ans:

A Relational database is a digital database based on the relational model of data, as proposed by E. F. Codd in 1970. A software system used to maintain relational databases is a relational database management system (RDBMS).

Examples of database server are- Oracle, DB2, Informix, and Microsoft SQL Serveretc

Q-13.What is difference between primary key and candidate key ?

Ans:

Sr. No.	Key	Primary Key	Candidate key
1	Definition	Primary Key is a unique and non-null key which identify a record uniquely in table. A table can have only one primary key.	Candidate key is also a unique key to identify a record uniquely in a table but a table can have multiple candidate keys.
2	Null	Primary key column value can not be null.	Candidate key column can have null value.
3	Objective	Primary key is most important part of any relation or table.	Candidate key signifies as which key can be used as Primary Key.
4	Use	Primary Key is a candidate key.	Candidate key may or may not be a primary key.

Q-14.Draw an E-R diagram of Hotel Management

Ans: