Introduction to Normalization and 1NF MCQs: 12 Solved Questions

Normalization questions often mix atomic values, redundancy and modification anomalies. A relation can satisfy 1NF because every cell is atomic and still suffer update, insertion and deletion anomalies that later normal forms address. First decide whether the issue is representation, dependency structure or a read-performance trade-off, then choose an option before reading its explanation. After practising 1NF, continue with the broader DBMS normalization MCQ set, which moves through 2NF, 3NF and BCNF.

Related reading: Database normalization and Normalization MCQs.

Normalization and 1NF in one worked relation

Normalization is controlled decomposition that reduces avoidable redundancy and prevents insertion, update and deletion anomalies while preserving the information represented by the schema. First Normal Form is narrower: every attribute value must be atomic for its declared domain, with no repeating groups, lists, sets or relation-valued cells. It does not test partial or transitive dependencies.

STUDENT_COURSES_RAW(StudentID, StudentName, Courses) contains (101, Asha, {DB201, CN202}) and (102, Rohan, {DB201}). Each Courses value is a set, not one course code, so the relation is not in 1NF. Convert it to ENROLMENT_1NF(StudentID, StudentName, CourseCode), with composite primary key (StudentID, CourseCode):

Every cell is now atomic, so the relation is in 1NF. Yet StudentID -> StudentName still creates modification anomalies. Changing Asha to Asha Jain needs two row updates. Deleting (102, Rohan, DB201) loses the only fact about Rohan. Student (103, Meera) cannot be stored without a course or a missing key component.

The next decomposition is STUDENT(StudentID PK, StudentName) with (101, Asha), (102, Rohan), (103, Meera), plus ENROLMENT(StudentID FK, CourseCode, PK(StudentID, CourseCode)) with (101, DB201), (101, CN202), (102, DB201). This goes beyond the 1NF test by removing a partial dependency. See Normalization in DBMS: 1NF to BCNF for the dependency rules behind the later forms.

MCQs 1-3: why normalization is applied

Question 1

In RDBMS, different classes of relations are created using __________ technique to prevent modification anomalies.

• A. Functional Dependencies

• B. Data integrity

• C. Referential integrity

• D. Normal Forms

Answer: D. Normal Forms. Normal-form rules define the resulting classes of relations and help prevent inconsistent copies of a fact. Functional dependencies help diagnose and justify decomposition, but they do not name those classes.

Solved question.

Question 2

Relational database schema normalization is NOT for :

• A. reducing the number of joins required to satisfy a query.

• B. eliminating uncontrolled redundancy of data stored in the database.

• C. eliminating number of anomalies that could otherwise occur with inserts and deletes.

• D. ensuring that functional dependencies are enforced.

Answer: A. Normalization often replaces one wide relation with several narrower ones, so combined facts may require more joins. Controlled redundancy, fewer anomalies and properly represented dependencies are design goals. Reducing joins is a performance concern that can motivate selective denormalization.

Solved question.

Question 3

Which of the following statements best describes the main reasons for normalizing relational database?

( I ) To achieve physical data independence.

( II ) To remove data anomalies (insertion, update, deletion anomalies).

( III ) To save space on disk.

• A. (I), (II) and (III)

• B. (I) and (II) only

• C. (I) and (III) only

• D. (II) and (III) only

Answer: D. Statement II is the central reason. In this question's framing, removing duplication can also save space, although keys and indexes mean that saving is not guaranteed. Physical data independence concerns separation between logical and physical schema levels.

Solved question.

MCQs 4-6: database terms and atomic values

Question 4

Match the following database terms to their functions:

List I

(a) Normalization

(b) Data Dictionary

(c) Referential Integrity

(d) External Schema

List II

(i) Enforces a match of primary key to foreign key

(ii) Reduces data redundancy in a database

(iii) Defines views of the database for particular users

(iv) Contains metadata describing database structure

Codes:

• A. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)

• B. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)

• C. (a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)

• D. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

Answer: B. Normalization reduces avoidable redundancy, a data dictionary stores schema metadata, referential integrity matches foreign keys to referenced keys, and an external schema presents a user-specific view. Thus the mapping is (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii).

Solved question.

Question 5

A relation is ______ if every field contains only atomic values that is, no lists or sets.

• A. 1NF

• B. 2NF

• C. 3NF

• D. BCNF

Answer: A. 1NF. Atomic values and no lists, sets or repeating groups define First Normal Form. This condition alone says nothing about partial or transitive dependencies, so it cannot establish 2NF, 3NF or BCNF.

Solved question.

Question 6

Which of the following violates the rules of First Normal Form (1NF)?

• A. A row with a column storing multiple email addresses as a comma-separated list

• B. A column with NULL values

• C. A column that stores phone numbers as VARCHAR

• D. A table with a composite primary key

Answer: A. The comma-separated field packs several email values into one cell, so it is not atomic. A composite key and a VARCHAR phone number do not violate 1NF. A NULL is a separate modelling and constraint issue, not the repeating-value defect tested here.

Solved question.

MCQs 7-9: repeating groups and nested relations

Question 7

The main task carried out in the __________ is to remove repeating attributes to separate tables.

• A. First Normal Form

• B. Second Normal Form

• C. Third Normal Form

• D. Fourth Normal Form

Answer: A. First Normal Form. 1NF removes repeating groups by placing one value in each field and representing repeated values as separate rows or a related relation. Later forms assume 1NF before testing stronger dependency conditions.

Solved question.

Question 8

At what level of normalization must the database be implemented as a single table with no repeating columns ?

• A. 1NF

• B. 2NF

• C. 3NF

• D. 4NF

Answer: A. 1NF. No repeating columns is the clue. Treat single table as wording about the relation being tested, not a claim that a normalized database must contain only one table. Normalization commonly creates several related tables.

Solved question.

Question 9

Which of the following normal form of normalization in relational model, disallows relations within relations or relations as attribute values within tuples?

• A. Fourth

• B. First

• C. Second

• D. Third

Answer: B. First. 1NF requires attribute positions to draw values from atomic domains, so a complete relation cannot occupy one attribute value inside a tuple. Later normal forms add dependency rules after this flat-relation condition is satisfied.

Solved question.

MCQs 10-12: normalization goals and the performance trade-off

Question 10

Which technique improves read performance in databases at the cost of redundancy ?

• A. Indexing

• B. Normalization

• C. Denormalization

• D. Partitioning

Answer: C. Denormalization. It deliberately duplicates or precombines facts so selected reads can avoid joins, accepting more storage and stricter update discipline. Indexing and partitioning are not defined by logical duplication. Normalization moves in the opposite direction by separating facts.

Solved question.

Question 11

Which of the following statements about normalization is correct ?

• A. Normalization removes redundant data in a database

• B. Normalization is used to add more redundancy in the database

• C. Normalization improves the performance of SQL queries

• D. Normalization is not needed in DBMS

Answer: A. More precisely, normalization reduces avoidable or uncontrolled redundancy, not every repeated value in every design. Faster SQL is not guaranteed because decomposition can add joins. Option B describes denormalization, while D rejects a core relational-design technique.

Keep practising this topic on the linked practice-module hub.

Question 12

What is the goal of normalization in database design?

• A. To improve data redundancy.

• B. To reduce data anomalies (insertions, deletions, updates).

• C. To optimize query performance.

• D. All of these.

Answer: B. Normalization stores each independent fact in the appropriate relation to reduce insertion, deletion and update anomalies. More redundancy is not the design aim, and faster queries are not guaranteed. Therefore All of these cannot be correct.

Solved question.

Introduction to normalization and 1NF: four traps to check

1. Atomic does not mean physically indivisible. Judge atomicity against the declared domain and needed operations. One phone number can be text, but 9876501111, 9876502222 packs two phone values into one cell.

2. 1NF does not mean anomaly-free. After checking cells and repeating groups, inspect dependencies. ENROLMENT_1NF repeats Asha because StudentID -> StudentName depends on only part of its composite key.

3. Normalization does not guarantee faster queries. It can add joins. Denormalization may accelerate selected reads, but duplicated facts must remain consistent.

4. Normalization does not remove every duplicate. It reduces avoidable redundancy while maintaining lossless reconstruction and, where required, dependency preservation. Use the CS Fundamentals for Placements route to revise DBMS with other core CS subjects.

The short version and the next practice step

First ask whether every cell holds one atomic value and whether repeating groups or nested relations exist. Then inspect the remaining functional dependencies and the anomalies they can cause. 1NF fixes representation; 2NF, 3NF and BCNF tighten dependency structure.

Attempt the 12 questions again without explanations. Record each miss under purpose, 1NF representation, dependency or performance trade-off; that error log gives you a better revision target than the score alone.

For a structured GATE CS path, use GATE Guidance by Sanchit Sir. For a placement-focused route through DBMS, operating systems and computer networks, CS Fundamentals for Placements by Sanchit Sir is the narrower alternative. Neither course is required to use this practice set.