This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Computer Science Chapter 3 Database Management Systems – Quiz 41 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Computer Science Chapter 3 Database Management Systems Quiz 41 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which SQL statement is used to insert new data in database? A) INSERT INTO. B) UPDATE. C) ADD. D) INSERT NEW. Show Answer Correct Answer: A) INSERT INTO. 2. Which CSS property is used to change the text color of an element? A) Background-color. B) Font-color. C) Text-color. D) Color. Show Answer Correct Answer: D) Color. 3. Which of the following best describes a key-value store? A) Stores data in a structured format. B) Organizes data in a tree-like structure. C) Stores data as key-value pairs. D) Uses a graph structure for relationships. Show Answer Correct Answer: C) Stores data as key-value pairs. 4. What is an index in SQL and how does it improve query performance? A) An index in SQL is a command that compiles SQL queries into machine code. B) An index in SQL is used to delete records from a database. C) An index in SQL is a database object that enhances query performance by allowing faster data retrieval. D) An index in SQL is a type of data type that stores large amounts of data. Show Answer Correct Answer: C) An index in SQL is a database object that enhances query performance by allowing faster data retrieval. 5. When analog signal to another analog signal conversion is required? A) To extend the area coverage of wires signal. B) To transmit analog signal through cables. C) To extend network cable. D) To connect computer with connectivity devices. Show Answer Correct Answer: A) To extend the area coverage of wires signal. 6. ..... is used to eliminate duplicate rows A) UNIQUE. B) NO DUPLICATE. C) DISTINCT. D) None of these. Show Answer Correct Answer: C) DISTINCT. 7. What are cursors in SQL and when would you use them? A) Cursors are used in SQL to process individual rows returned by a query, allowing for row-by-row operations. B) Cursors are used to optimize query performance by executing multiple queries simultaneously. C) Cursors are used to create temporary tables for storing large datasets. D) Cursors are a type of SQL function that automatically updates all rows in a table at once. Show Answer Correct Answer: A) Cursors are used in SQL to process individual rows returned by a query, allowing for row-by-row operations. 8. What is the primary purpose of a database schema in a DBMS? A) To define the structure and organisation of data in the database. B) To display data in graphical form. C) To print documents. D) To connect to the internet. Show Answer Correct Answer: A) To define the structure and organisation of data in the database. 9. What are the main components of a database system structure? A) Database backup system. B) Network configuration tools. C) Data visualization software. D) The main components of a database system structure are the database engine, database schema, query processor, and user interface. Show Answer Correct Answer: D) The main components of a database system structure are the database engine, database schema, query processor, and user interface. 10. What is an essential feature of a database management system to ensure that patient data is not lost? A) Manual data entry. B) Regular data backups. C) Store data in plain text. D) Open access to all users. Show Answer Correct Answer: B) Regular data backups. 11. What is the primary purpose of using SELECT, INSERT, UPDATE, and DELETE commands in SQL? A) To modify the SQL software. B) To control user access and permissions. C) To manage data in a database. D) To configure network settings. Show Answer Correct Answer: C) To manage data in a database. 12. Which activity is part of the group task related to database systems? A) Creating a database for banking systems. B) Comparing the ease of access, security, and cost of paper-based and digital systems. C) Designing a Netflix recommendation system. D) Calculating grades using Excel. Show Answer Correct Answer: B) Comparing the ease of access, security, and cost of paper-based and digital systems. 13. Which SQL clause is used to combine the result sets of two or more SELECT statements? A) UNION. B) JOIN. C) MERGE. D) LINK. Show Answer Correct Answer: A) UNION. 14. What is the transformation of requests and results from one level to another called? A) Mapping. B) Schema. C) Data Independence. D) None of the above. Show Answer Correct Answer: A) Mapping. 15. Lock:A mechanism that restricts ..... to a data item. A) Access. B) Deletion. C) Creation. D) Modification. Show Answer Correct Answer: A) Access. 16. What is an ER diagram and what are its basic components? A) Entities, attributes, and diagrams. B) Attributes, relationships, and tables. C) Entities, relationships, and keys. D) The basic components of an ER diagram include entities, attributes, and relationships. Show Answer Correct Answer: D) The basic components of an ER diagram include entities, attributes, and relationships. 17. What are the main types of SQL joins? A) EXTERNAL JOIN, INNER OUTER JOIN, LEFT OUTER JOIN. B) CROSS JOIN, SELF JOIN, NATURAL JOIN. C) JOIN ALL, PARTIAL JOIN, COMPOSITE JOIN. D) INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN. Show Answer Correct Answer: D) INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN. 18. Which command would you use to remove a column from an existing table in SQL? A) DELETE COLUMN. B) REMOVE COLUMN. C) DROP COLUMN. D) ALTER COLUMN. Show Answer Correct Answer: C) DROP COLUMN. 19. Which clause is used to filter groups created by the GROUP BY clause? A) WHERE. B) HAVING. C) ORDER BY. D) LIMIT. Show Answer Correct Answer: B) HAVING. 20. What is the maximum number of characters allowed in text field is access? A) 255. B) 256. C) 64000. D) 65000. Show Answer Correct Answer: A) 255. 21. In a banking system within a certain Ethiopian business banks, two transactions attempt to withdraw from the same account simultaneously. Which technique helps prevent data inconsistency? A) Implementing Two-Phase Locking (2PL). B) Running both transactions in parallel. C) Creating more database indexes. D) Using a NoSQL database. Show Answer Correct Answer: A) Implementing Two-Phase Locking (2PL). 22. Hey there, database wizards! Can you help ALYA MAISARA, AISYAH NAJIHAH, and ANIS SOFIA figure out the different normal forms in database normalization? A) 1NF, 2NF, 3NF, 6NF. B) 1NF, 2NF, 3NF, 4NF, 7NF. C) 1NF, 2NF, 3NF, 5NF, 8NF. D) 1NF, 2NF, 3NF, BCNF, 4NF, 5NF. Show Answer Correct Answer: D) 1NF, 2NF, 3NF, BCNF, 4NF, 5NF. 23. What is the output of a Cartesian product? A) Multiple relations. B) Combined records. C) No records. D) Single relation. Show Answer Correct Answer: B) Combined records. 24. What is the purpose of the domain relational calculus? A) To simplify queries. B) To create new schemas. C) To use domain variables. D) To define relations. Show Answer Correct Answer: C) To use domain variables. 25. Which of the following is a disadvantage of a database system compared to a traditional file-processing system? A) Lower data integrity. B) Increased data redundancy. C) Greater complexity and higher initial cost. D) Poor data security. Show Answer Correct Answer: C) Greater complexity and higher initial cost. ← 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