Chapter Exam

Chapter-8 Database Concepts — Online MCQ Test

Q: Which of the following is the definition of a tuple?

Answer: B. A row in a relational table — A tuple is a single row in a relational table that contains a set of attribute values.

Q: In a Student table with columns (StudentID, Name, Email, Phone), what is the degree of this relation?

Answer: D. 4 — The degree is the number of attributes (columns), which are StudentID, Name, Email, and Phone = 4 attributes.

Q: Analyze this situation: Table Course has CourseID as primary key. Table Enrollment has StudentID, CourseID. CourseID in Enrollment is marked as foreign key. What constraint is being enforced?

Answer: B. Referential integrity only — The foreign key CourseID enforces referential integrity by ensuring every CourseID in Enrollment exists in the Course table's primary key.

COMPUTER SCIENCE · CLASS 12 SECOND PUC · Karnataka State Board

Practice Chapter-8 Database Concepts with a free chapter-wise online MCQ test for Karnataka State Board CLASS 12 SECOND PUC COMPUTER SCIENCE. This chapter covers: relational model - primary key - candidate key - foreign key - attributes - tuples - cardinality - degree. AI-generated questions from basic to board-exam level, with instant results and explanations.

Questions

20m

Time Limit

Attempts Left

10 random questions from this chapter (mixed difficulty)
Questions you've seen before won't repeat until the pool resets
You have 20 minutes — exam auto-submits when time is up
Maximum 3 attempts per chapter
Results and explanations shown immediately after submission

New here? Register free — includes 3 free chapter exams.

Chapter-8 Database Concepts — Important Questions & Answers (FAQ)

Frequently asked questions from Karnataka State Board CLASS 12 SECOND PUC COMPUTER SCIENCE — Chapter-8 Database Concepts, with answers and explanations. These are sample questions; the exam has its own separate question set.

What is a relation in the relational model?

A. A mathematical concept represented as a table with rows and columns ✓
B. A connection between two databases
C. A type of primary key constraint
D. A method of organizing files sequentially

Answer: A. A mathematical concept represented as a table with rows and columns
In the relational model, a relation is a table consisting of rows (tuples) and columns (attributes) that represent data.

Which of the following is the definition of a tuple?

A. A column in a relational table
B. A row in a relational table ✓
C. A data type used in databases
D. A constraint applied to attributes

Answer: B. A row in a relational table
A tuple is a single row in a relational table that contains a set of attribute values.

In a Student table with columns (StudentID, Name, Email, Phone), what is the degree of this relation?

A. 1
B. 2
C. 3
D. 4 ✓

Answer: D. 4
The degree is the number of attributes (columns), which are StudentID, Name, Email, and Phone = 4 attributes.

Analyze this situation: Table Course has CourseID as primary key. Table Enrollment has StudentID, CourseID. CourseID in Enrollment is marked as foreign key. What constraint is being enforced?

A. Entity integrity only
B. Referential integrity only ✓
C. Both entity and referential integrity
D. Domain integrity only

Answer: B. Referential integrity only
The foreign key CourseID enforces referential integrity by ensuring every CourseID in Enrollment exists in the Course table's primary key.

[TRICKY] In a table with attributes (EmployeeID, Email, PhoneNumber), if Email is NULL for some records and PhoneNumber for others, but EmployeeID is always non-NULL and unique, then:

A. Email or PhoneNumber could individually serve as a primary key
B. Only EmployeeID can be a primary key due to NULL values in other attributes ✓
C. A composite key of (Email, PhoneNumber) is better than EmployeeID alone
D. No primary key can be established for this table

Answer: B. Only EmployeeID can be a primary key due to NULL values in other attributes
Primary keys cannot contain NULL values; therefore, only EmployeeID with guaranteed uniqueness and non-NULL values can be the primary key.