Informatics Practices Class 11: Unit -3 MCQs

 Unit 3: Database concepts and the Structured Query Language 

Database Concepts: Introduction to database concepts and its need, Database Management System.

Relational data model: Concept of domain, tuple, relation, candidate key, primary key, alternate key

Advantages of using Structured Query Language, Data Definition Language, Data Query Language and Data Manipulation Language, Introduction to MySQL, creating a database using MySQL, Data Types

Data Definition: CREATE DATABASE, CREATE TABLE, DROP, ALTER

Data Query: SELECT, FROM, WHERE with relational operators, BETWEEN, logical 

operators, IS NULL, IS NOT NULL

Data Manipulation: INSERT, DELETE, UPDATE

[24/07, 7:04 PM] Meta AI: Here are some MCQs on the topic "Database Concepts" with explanations:

MCQ 1:

What is the primary purpose of a database management system (DBMS)?

A) To store data

B) To manage data

C) To secure data

D) To recover data

Answer: B) To manage data

Explanation: A DBMS is a software system that manages and controls access to a database, allowing users to perform various operations like creating, updating, and querying data.

MCQ 2:

Which type of database uses tables to store data?

A) Hierarchical database

B) Network database

C) Relational database

D) Object-oriented database

Answer: C) Relational database

Explanation: Relational databases use tables (also known as relations) to store data, with well-defined relationships between tables.

MCQ 3:

What is data normalization?

A) The process of dividing large tables into smaller tables

B) The process of combining small tables into larger tables

C) The process of securing data

D) The process of recovering data

Answer: A) The process of dividing large tables into smaller tables

Explanation: Data normalization is the process of organizing data to minimize data redundancy and improve data integrity, involving dividing large tables into smaller tables with well-defined relationships.

MCQ 4:

What is the main advantage of using a relational database?

A) Improved data security

B) Improved data integrity

C) Improved data scalability

D) All of the above

Answer: D) All of the above

Explanation: Relational databases offer improved data security, integrity, and scalability due to their structured and organized approach to storing data.

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[24/07, 7:11 PM] Meta AI: Here are some more MCQs on the topic "Database Concepts" with explanations:

MCQ 5:

What is the purpose of a primary key in a relational database?

A) To uniquely identify each record

B) To establish relationships between tables

C) To index data for faster retrieval

D) To secure data from unauthorized access

Answer: A) To uniquely identify each record

Explanation: A primary key is a unique identifier for each record in a table, ensuring that no two records have the same primary key value.

MCQ 6:

Which of the following is a characteristic of a hierarchical database?

A) Data is stored in tables

B) Data is stored in a tree-like structure

C) Data is stored in a graph-like structure

D) Data is stored in an object-oriented structure

Answer: B) Data is stored in a tree-like structure

Explanation: Hierarchical databases store data in a tree-like structure, with a single parent-child relationship between data elements.

MCQ 7:

What is data denormalization?

A) The process of normalizing data

B) The process of denormalizing data

C) The process of optimizing data for faster retrieval

D) The process of securing data from unauthorized access

Answer: C) The process of optimizing data for faster retrieval

Explanation: Data denormalization involves intentionally de-normalizing data to improve query performance, often by duplicating data or combining tables.

MCQ 8:

Which of the following is a benefit of using a database management system (DBMS)?

A) Improved data security

B) Improved data integrity

C) Improved data scalability

D) All of the above

Answer: D) All of the above

Explanation: A DBMS offers improved data security, integrity, and scalability, as well as support for multiple users and applications.

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[24/07, 7:12 PM] Meta AI: Here are some more MCQs on the topic "Database Concepts" with explanations:

MCQ 9:

What is the purpose of an index in a database?

A) To uniquely identify each record

B) To establish relationships between tables

C) To speed up data retrieval

D) To secure data from unauthorized access

Answer: C) To speed up data retrieval

Explanation: An index is a data structure that improves query performance by allowing the database to quickly locate specific data.

MCQ 10:

Which of the following is a type of database constraint?

A) Primary key

B) Foreign key

C) Unique constraint

D) All of the above

Answer: D) All of the above

Explanation: Database constraints include primary keys, foreign keys, unique constraints, and check constraints, which help maintain data consistency and accuracy.

MCQ 11:

What is the purpose of a view in a database?

A) To create a new table

B) To modify an existing table

C) To provide a virtual table based on a query

D) To secure data from unauthorized access

Answer: C) To provide a virtual table based on a query

Explanation: A view is a virtual table based on a query, allowing users to access data without modifying the underlying tables.

MCQ 12:

Which of the following is a benefit of data normalization?

A) Improved data security

B) Improved data integrity

C) Reduced data redundancy

D) All of the above

Answer: D) All of the above

Explanation: Data normalization improves data security, integrity, and scalability, while reducing data redundancy and improving data consistency.

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[24/07, 7:12 PM] Meta AI: Here are some more MCQs on the topic "Database Concepts" with explanations:

MCQ 13:

What is the purpose of a transaction in a database?

A) To execute a single query

B) To execute multiple queries as a single unit

C) To secure data from unauthorized access

D) To improve data retrieval performance

Answer: B) To execute multiple queries as a single unit

Explanation: A transaction is a sequence of operations performed as a single, all-or-nothing unit, ensuring data consistency and integrity.

MCQ 14:

Which of the following is a type of database join?

A) Inner join

B) Outer join

C) Left join

D) All of the above

Answer: D) All of the above

Explanation: Database joins include inner joins, outer joins, left joins, right joins, and full outer joins, which combine data from multiple tables.

MCQ 15:

What is the purpose of a stored procedure in a database?

A) To execute a single query

B) To execute multiple queries as a single unit

C) To encapsulate complex logic and reuse code

D) To secure data from unauthorized access

Answer: C) To encapsulate complex logic and reuse code

Explanation: A stored procedure is a precompiled SQL program that encapsulates complex logic and can be reused, improving performance and maintainability.

MCQ 16:

Which of the following is a benefit of using a database?

A) Improved data security

B) Improved data integrity

C) Improved data scalability

D) All of the above

Answer: D) All of the above

Explanation: Using a database provides improved data security, integrity, and scalability, as well as support for multiple users and applications.

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