10 Normalization MCQ DBMS

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Multiple-Choice Questions on Normalization and Normal Forms in DBMS for UGC NET, GATE, SET, ISRO and other exams 

Question 1: Normalization Definition

Q1: Normalization in a database is a process of:

  • A) Reducing data redundancy and improving data integrity

  • B) Increasing data redundancy for faster access

  • C) Encrypting the database

  • D) Creating more tables

Answer: A) Reducing data redundancy and improving data integrity

Explanation: Normalization is a systematic approach to organizing data in a database to minimize redundancy and ensure data integrity. It involves decomposing larger tables into smaller, well-structured tables while maintaining relationships among data.

Question 2: First Normal Form (1NF)

Q2: A table is in the First Normal Form (1NF) if:

  • A) All values in the table are atomic and there are no repeating groups

  • B) It contains no partial dependencies

  • C) It contains no transitive dependencies

  • D) It is free of all anomalies

Answer: A) All values in the table are atomic and there are no repeating groups

Explanation: The First Normal Form (1NF) requires that all columns in a table contain only atomic values (indivisible values) and that there are no repeating groups or arrays in a single column.

Question 3: Second Normal Form (2NF)

Q3: A table is in the Second Normal Form (2NF) if:

  • A) It is in 1NF and there are no partial dependencies

  • B) It is in 1NF and contains no transitive dependencies

  • C) It is in 1NF and all non-key attributes are fully functionally dependent on the primary key

  • D) It is in 3NF

Answer: A) It is in 1NF and there are no partial dependencies

Explanation: The Second Normal Form (2NF) builds upon 1NF by ensuring that all non-key attributes are fully dependent on the entire primary key, meaning there should be no partial dependencies (where a non-key attribute depends only on part of a composite key).

Question 4: Third Normal Form (3NF)

Q4: A table is in the Third Normal Form (3NF) if:

  • A) It is in 2NF and all non-key attributes are fully functionally dependent on the primary key

  • B) It is in 2NF and contains no transitive dependencies

  • C) It is in 1NF and there are no repeating groups

  • D) It is free of all anomalies

Answer: B) It is in 2NF and contains no transitive dependencies

Explanation: The Third Normal Form (3NF) ensures that all attributes depend only on the primary key and not on other non-key attributes. This removes transitive dependencies, where one non-key attribute is dependent on another non-key attribute.

Question 5: Boyce-Codd Normal Form (BCNF)

Q5: A table is in Boyce-Codd Normal Form (BCNF) if:

  • A) It is in 3NF and every determinant is a candidate key

  • B) It is in 2NF and contains no transitive dependencies

  • C) It is in 1NF and contains no repeating groups

  • D) It is free of all anomalies

Answer: A) It is in 3NF and every determinant is a candidate key

Explanation: BCNF is a stricter version of 3NF, ensuring that every determinant (a column that functionally determines another column) is a candidate key, eliminating potential anomalies that may still exist in 3NF.

Question 6: Functional Dependency

Q6: In a relational database, a functional dependency occurs when:

  • A) One attribute uniquely determines another attribute

  • B) An attribute depends on multiple attributes

  • C) An attribute is independent of other attributes

  • D) Multiple attributes determine a single attribute

Answer: A) One attribute uniquely determines another attribute

Explanation: Functional dependency means that if you know the value of one attribute, you can uniquely determine the value of another attribute. For example, in a student database, the student ID uniquely determines the student’s name.

Question 7: Partial Dependency

Q7: A partial dependency exists in a table when:

  • A) A non-key attribute depends on part of a composite primary key

  • B) A non-key attribute depends on the entire primary key

  • C) A non-key attribute depends on another non-key attribute

  • D) A primary key depends on a non-key attribute

Answer: A) A non-key attribute depends on part of a composite primary key

Explanation: Partial dependency occurs when a non-key attribute depends on only part of a composite primary key. This issue exists in 1NF and is eliminated in 2NF by ensuring that all attributes depend on the whole primary key.

Question 8: Transitive Dependency

Q8: A transitive dependency exists in a table when:

  • A) A non-key attribute depends on another non-key attribute

  • B) A non-key attribute depends on the primary key

  • C) The primary key depends on a non-key attribute

  • D) A primary key depends on part of a composite key

Answer: A) A non-key attribute depends on another non-key attribute

Explanation: A transitive dependency occurs when a non-key attribute depends on another non-key attribute rather than directly on the primary key. This is removed in 3NF.

Question 9: Fourth Normal Form (4NF)

Q9: A table is in the Fourth Normal Form (4NF) if:

  • A) It is in BCNF and has no multi-valued dependencies

  • B) It is in 3NF and contains no transitive dependencies

  • C) It is in 2NF and all non-key attributes are fully functionally dependent on the primary key

  • D) It is in 1NF and contains no repeating groups

Answer: A) It is in BCNF and has no multi-valued dependencies

Explanation: The Fourth Normal Form (4NF) removes multi-valued dependencies, which occur when one key determines multiple independent values for another column. This ensures that the data is stored in separate tables when necessary.

Question 10: Fifth Normal Form (5NF)

Q10: A table is in the Fifth Normal Form (5NF) if:

  • A) It is in 4NF and is decomposed into smaller tables to eliminate redundancy

  • B) It is in 3NF and contains no transitive dependencies

  • C) It is in 2NF and all non-key attributes are fully functionally dependent on the primary key

  • D) It is in BCNF and has no multi-valued dependencies

Answer: A) It is in 4NF and is decomposed into smaller tables to eliminate redundancy

Explanation: The Fifth Normal Form (5NF) deals with eliminating redundancy by decomposing tables into smaller ones while preserving the ability to reconstruct the original data without loss. It ensures that there are no join dependencies that could lead to anomalies.

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