This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 20 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 20 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What does the SELECT statement do in SQL? A) Retrieves data from a database. B) Updates data in a database. C) Deletes data from a database. D) Creates a new database. Show Answer Correct Answer: A) Retrieves data from a database. 2. What is the main method to update data in files? A) Database transactions. B) Automated scripts. C) Direct editing. D) Copy-paste. Show Answer Correct Answer: D) Copy-paste. 3. What is the primary data model used for data storage and processing? A) Network Model. B) Object-Oriented Model. C) Relational Model. D) Hierarchical Model. Show Answer Correct Answer: C) Relational Model. 4. What is a limitation of file-based systems? A) Data inconsistency and confusion. B) Data is stored in a centralized manner. C) Data is easily shared. D) Data is always secure. Show Answer Correct Answer: A) Data inconsistency and confusion. 5. How does a DBMS ensure data security? A) By implementing access controls and backup procedures. B) By allowing all users to modify data. C) By storing data in unstructured formats. D) By preventing queries from being executed. Show Answer Correct Answer: A) By implementing access controls and backup procedures. 6. What is a major issue caused by storing an employee's name and address in multiple places in traditional file systems? A) Increased security. B) Data redundancy and integrity problems. C) Faster data access. D) Easier data updates. Show Answer Correct Answer: B) Data redundancy and integrity problems. 7. What is the significance of databases in big data and analytics? A) Databases handle large volumes of data with speed and efficiency. B) Databases are not useful for analytics. C) Databases only store data in text files. D) Databases do not support real-time operations. Show Answer Correct Answer: A) Databases handle large volumes of data with speed and efficiency. 8. How are null values represented in a relational database? A) As the number 0. B) As an empty string. C) As a special marker or indicator. D) Null values are not allowed in relational databases. Show Answer Correct Answer: C) As a special marker or indicator. 9. What do tables in RDBMS consist of? A) Rows and columns. B) Only columns. C) Only rows. D) Only keys. Show Answer Correct Answer: A) Rows and columns. 10. The four main objects of a database consist of: A) Form, table, query, report. B) Filter, table, database, query. C) Form, data type, record, query. D) Form, record, field, report. Show Answer Correct Answer: A) Form, table, query, report. 11. What does tuple relational calculus describe? A) Database design. B) Nonprocedural queries. C) Data types. D) Procedural queries. Show Answer Correct Answer: B) Nonprocedural queries. 12. In SQL, what is a subquery? A) A query that is nested inside another query. B) A query that modifies the database structure. C) A query that deletes records. D) A query that creates a new table. Show Answer Correct Answer: A) A query that is nested inside another query. 13. What are the primary applications of database systems? A) Data encryption and security management. B) The primary applications of database systems include transaction processing, data analysis, data warehousing, and managing large datasets. C) Web hosting and server management. D) Graphic design and multimedia production. Show Answer Correct Answer: B) The primary applications of database systems include transaction processing, data analysis, data warehousing, and managing large datasets. 14. A set of possible data values is called A) Attributes. B) Tuple. C) Domain. D) Degree. Show Answer Correct Answer: C) Domain. 15. Provide an example of a DDL statement. A) DELETE FROM users WHERE id = 1;. B) CREATE TABLE users (id INT PRIMARY KEY, name VARCHAR(100), email VARCHAR(100));. C) SELECT * FROM users;. D) UPDATE users SET name = 'John' WHERE id = 1;. Show Answer Correct Answer: B) CREATE TABLE users (id INT PRIMARY KEY, name VARCHAR(100), email VARCHAR(100));. 16. Which of the following is the block that is not permitted to be written back to the disk? A) Dead code. B) Read only. C) Pinned. D) Zapped. Show Answer Correct Answer: C) Pinned. 17. Which one of the following matches the functions of a contemporary operating system? A) It does not ensure security and access control. B) It manages human resources. C) It enables single tasking. D) It enables multitasking. Show Answer Correct Answer: D) It enables multitasking. 18. What does the term 'normalization' aim to achieve in database design? A) Speed up data retrieval. B) Enhance data security. C) Reduce data anomalies. D) Increase data redundancy. Show Answer Correct Answer: C) Reduce data anomalies. 19. Which of the following is a key component of a DBMS that is responsible for managing data storage and access? A) Data Dictionary. B) Storage Manager. C) Query Processor. D) Transaction Manager. Show Answer Correct Answer: B) Storage Manager. 20. A ..... is system software for creating and managing databases. A) Views. B) Queries. C) Tables. D) DBMS. Show Answer Correct Answer: D) DBMS. 21. What does the term 'weak entity set' refer to? A) An entity with simple attributes. B) An entity that cannot exist alone. C) An entity with many attributes. D) An entity with no attributes. Show Answer Correct Answer: B) An entity that cannot exist alone. 22. What does the GROUP BY clause do? A) Deletes data. B) Groups data. C) Filters data. D) Sorts data. Show Answer Correct Answer: B) Groups data. 23. What is an instance in relation to a database schema? A) An instance is a specific set of data that conforms to a database schema. B) An instance is a collection of database schemas. C) An instance is a type of database schema. D) An instance is a blueprint for a database schema. Show Answer Correct Answer: A) An instance is a specific set of data that conforms to a database schema. 24. Grant and revoke are ..... statements. A) DDL. B) DML. C) TCL. D) DCL. Show Answer Correct Answer: D) DCL. 25. How does a DBMS address the issue of data inconsistency? A) By storing data in separate linked tables. B) By storing data in a single file. C) By validating the data entry. D) By compressing the data. Show Answer Correct Answer: C) By validating the data entry. ← PreviousNext →Related QuizzesClass 12 Computer Science Chapter 3 Database Management Systems Quiz 1Class 12 Computer Science Chapter 3 Database Management Systems Quiz 2Class 12 Computer Science Chapter 3 Database Management Systems Quiz 3Class 12 Computer Science Chapter 3 Database Management Systems Quiz 4Class 12 Computer Science Chapter 3 Database Management Systems Quiz 5Class 12 Computer Science Chapter 3 Database Management Systems Quiz 6Class 12 Computer Science Chapter 3 Database Management Systems Quiz 7Class 12 Computer Science Chapter 3 Database Management Systems Quiz 8Class 12 Computer Science Chapter 3 Database Management Systems Quiz 9Class 12 Computer Science Chapter 3 Database Management Systems Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books