Bangladesh Bank (Assistant Programmer)-2016

Bangladesh Bank (Assistant Programmer)-2016

Q-1.What is tautology? Show tautology with truth table- ((A->B)^B)->A

Ans: A tautology is a logical statement in which the conclusion is equivalent to the premise. Result true or false.

A	B	A->B	(A->B)^B	((A->B)^B)->A
F	T	T	T	F
F	F	T	F	T
T	T	T	T	T
T	F	F	F	T

Q-2.Show prefix and postfix notation of the following :(A+B)*C-(D-E)^(G-F)
Ans:
PREFIX: (A+B)*C-(D-E)^(G-F)

[+AB]*C-[-DE]^[-GF]

[*+ABC]-[^-DE-GF]

-*+ABC^-DE-GF

POSTFIX:(A+B)*C-(D-E)^(G-F)

[AB+]*C-[DE-]^[GF-]

[AB+C*]-[DE-GF-^]

AB+C*DE-GF-^-

Q-3.What is domain and workgroup? Write command to get MAC address

Ans:

Computers on a network can be part of a workgroup or a domain. The main difference between workgroups and domains is how resources on the network are managed. Computers on home networks are usually part of a workgroup, and computers on workplace networks are usually part of a domain.

In a workgroup:

All computers are peers; no computer has control over another computer.

Each computer has a set of user accounts. To use any computer in the workgroup, you must have an account on that computer.

There are typically no more than ten to twenty computers.

All computers must be on the same local network or subnet.

In a domain:

One or more computers are servers. Network administrators use servers to control the security and permissions for all computers on the domain. This makes it easy to make changes because the changes are automatically made to all computers.

If you have a user account on the domain, you can log on to any computer on the domain without needing an account on that computer.

There can be hundreds or thousands of computers.

The computers can be on different local networks.

MAC Address:

Windows 2000, 2003, XP, NT:

1. Click Start > Run.

A Run text box appears .

2. In the Run text box, type cmd.

3. Press Enter .
A command prompt displays.

4. In the command prompt, type ipconfig /all.

5. Press Enter .

Under Ethernet adapter Wireless Network Connection, a Physical Address displays. This is your computer’s Ethernet MAC address.

Linux/Unix:

1. Launch the terminal

2. Type fconfig in terminal

3. Your MAC address is displayed.

OS:

Select Settings > General > About.
A Wi-Fi Address displays. This is your device’s MAC address.

Android:

In most cases, you can follow this procedure to locate your MAC address:

Select Settings > About Device > Status.
A WiFi Address or WiFi MAC Address displays. This is your device’s MAC address.

Q-4.Define polymorphism. Difference between method overloading and overriding [Engineering College under PSC-2017]

Ans: Polymorphism: Polymorphism is the property of something having many forms. A thing that has many forms is polymorphic. Appropriately, and perhaps confusingly, its meaning takes many forms, notably in computer science and biology.

Polymorphism is considered as one of the important features of Object Oriented Programming. Polymorphism allows us to perform a single action in different ways.

Method Overloading VS Method Overriding:

Method overloading	Method overriding
Method overloading is a compile time polymorphism.	Method overriding is a run time polymorphism.
In case of method overloading, parameter must be different.	In case of method overriding, parameter must be same.
Method overloading is used to increase the readability of the program.	Method overriding is used to provide the specific implementation of the method that is already provided by its super class.
It is occur within the class.	While it is performed in two classes with inheritance relationship.
Method overloading may or may not require inheritance.	While method overriding always needs inheritance.
Overloaded methods use static binding.	Overridden methods use dynamic binding.
You can perform overloading on static methods.	You cannot perform overriding on static methods.

Q-5.Write code for Fibonacci series with and structural programming language

Ans:

#include <stdio.h>
#include <conio.h>
int main()
{
int i, n, f1 = 0, f2 = 1, nextTerm;
printf("Enter the number of terms: ");
scanf("%d", &n);
printf("Fibonacci Series: ");
for (i = 1; i<= n; i++)
{
printf("%d, ", f1);
nextTerm = f1 + f2;
f1 = f2;
f2 = nextTerm;
}
return 0;
}

Q-6. What are the minimum tags to write an HTML page? Write down

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>My Title</title>
<meta name="description" contents="The description of the site here">
</head>
<body>
Hello World!
</body>
</html>

Q-7. What is the integrity rule in database ?find out second highest salary from table

Ans: Integrity Rules:

The Relational Model includes two general integrity rules. These integrity rules implicitly or explicitly define the set of consistent database states, or changes of state, or both.

Those rules are summarized as follows:-

Entity Integrity:
Requirement: All primary key entries are unique, and no part of a primary key may be null.
Purpose: Each row will have a unique identity, and foreign key values can properly reference primary key values.

Example: No invoice can have a duplicate number, nor can it be null. In short, all invoices are uniquely identified by their invoice number.

Referential Integrity:

Requirement: A foreign key may have either a null entry, as long as it is not a part of its table’s primary key, or an entry that matches the primary key value in a table to which it is related. (Every non-null foreign key value must reference an existing primary key value.)

Purpose: It is possible for an attribute NOT to have a corresponding value, but it will be impossible to have an invalid entry. The enforcement of the referential integrity rule makes it impossible to delete a row in one table whose primary key has mandatory matching foreign key values in another table.

Example: A customer might not yet have an assigned sales representative (number), but it will be impossible to have an invalid sales representative (number).

Second highest salary:

SELECT max(salary)
FROM Employee
WHERE salary NOT IN (SELECT max(salary) FROM Employee);

Q-8. What is cardinality and modality ?

Ans: Cardinality: Maximum number of associations between the table rows.

“cardinality” in database design has to do with counting tables and values. With that said, cardinality has three main definitions. It can relate to counting the number of elements in a set, identifying the relationships between tables, or describing how database tables contain a number of values, and what those tables look like in general.

Types:- One-to-one, one-to-many, many-to-many.

Modality:Minimum number of row associations.

As cardinality is the maximum number of connections between table rows (either one or many), modality is the least number of row connections! Modality also only has two options, 0 being the least or 1 being the least.