Third Chapter Solved Exercise MCQs Of ICS Second Year Computer Science

Third Chapter Solved Exercise MCQs Of ICS Second Year Computer Science. Each question includes the correct answer and a brief explanation. It’s designed to help you study, prepare for exams, and understand key concepts better. Boost your Computer Science knowledge with these practice exercises.

Third chapter solved MCQs with explanation

1. Which of the following keys does not hold uniqueness property:
a) candidate key
b) foreign key
c) primary key
d) secondary key

Explanation: This answer is correct because a foreign key does not require uniqueness; it can have duplicate values that link to the primary key of another table.

2. An entity related to itself in an ERD model refers to:
a) recursive relationship
b) one-to-many relationship
c) many-to-many relationship
d) one-to-one relationship

Explanation: This answer is correct because a recursive relationship occurs when an entity in a database is related to itself, meaning it references the same entity.

3. Database development process involves mapping of conceptual data model into:
a) Object-oriented data model
b) Network data model
c) Implementation model
d) Hierarchical data model

Explanation: This answer is correct because, in some cases, conceptual models are mapped to network data models during the database development process.

4. In ERD model, the relationship between two entities is represented by a:
a) diamond symbol
b) rectangular box
c) oval symbol
d) line

Explanation: This answer is correct because in an Entity-Relationship Diagram (ERD), relationships between entities are typically represented by a line connecting them.

5. In hybrid distribution, which kind of fragments are stored at only one site:
a) critical fragments
b) non-critical fragments
c) critical and non-critical fragments
d) only large fragments

Explanation: This answer is correct because in a hybrid distribution, large fragments are often stored at a single site to reduce data redundancy and manage storage efficiently.

6. The UPDATE command is used to:
a) delete records from a table
b) retrieve data from a table
c) modify existing records in a table
d) create a new table

Explanation: This answer is correct because the UPDATE command in SQL is used to modify or change existing records in a table.

7. The UNIQUE constraint in a database is used to:
a) ensure a column cannot be null
b) ensure all values in a column are different
c) link tables together
d) enforce a primary key

Explanation: This answer is correct because the UNIQUE constraint ensures that all values in a specific column are distinct and do not repeat.

8. Which SQL clause is used to sort the result set?
a) WHERE
b) ORDER BY
c) GROUP BY
d) HAVING

Explanation: This answer is correct because the ORDER BY clause in SQL is used to sort the result set by one or more columns.

9. The DELETE command is used to:
a) remove records from a table
b) update records in a table
c) create a new table
d) retrieve data from a table

Explanation: This answer is correct because the DELETE command is used to remove records from an existing table in a database.

10. Which of the following is a DDL (Data Definition Language) command?
a) CREATE
b) INSERT
c) UPDATE
d) SELECT

Explanation: This answer is correct because CREATE is a DDL command used to define and create new structures in the database, such as tables and schemas.