Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
41
In the ANSI/SPARC architecture, the internal level corresponds to the:
Answer:
Physical level
The ANSI/SPARC three-level architecture defines the internal, conceptual, and external levels. The internal level is synonymous with the physical level, dealing with the physical storage of data.
42
A metadata repository in a DBMS that stores information about the database structure is called a:
Answer:
Data Dictionary
The data dictionary, also known as the metadata repository, is a system file that stores data-about-data. It contains definitions of all schema objects, such as table names, column names, data types, and constraints.
43
Which SQL command is used to remove a column from a table?
Answer:
ALTER TABLE table_name DROP COLUMN column_name
The `ALTER TABLE` command is used to modify the structure of an existing table, and the `DROP COLUMN` clause is used to delete a specific column.
44
_ means data is independent of applications, so changes in data don’t require changes in forms or reports.
Answer:
Data independence
Data independence is the ability to modify a schema definition in one level without affecting a schema definition in the next higher level.
45
Which aggregate function would you use to find the highest salary from an `Employees` table?
Answer:
`MAX(Salary)`
The `MAX()` function returns the largest value from the selected column.
46
An application or program that interacts with the database by sending requests or commands is known as a:
Answer:
Database Client
A database client (or frontend) is the application that enables users to interact with the database server (or backend). It sends queries to the server and displays the results.
47
Third Normal Form (3NF) is designed to ensure that there are no non-key attributes that depend on other non-key attributes. This type of dependency is called:
Answer:
A. Partial Dependency
3NF directly addresses and eliminates transitive functional dependencies. This is where a non-key attribute is determined by another non-key attribute, rather than directly by the primary key.
48
In the relational model, relationships between tables are established through:
Answer:
Foreign keys
The relational model does not use physical pointers. Instead, it creates logical links between tables by placing the primary key of one table into another table, where it becomes a foreign key.
49
What is a major advantage of the relational model over the hierarchical and network models?
Answer:
It has greater data independence.
The relational model provides a high degree of data independence. This means the logical structure of the data (how users see it) is separate from its physical storage structure. This allows administrators to change storage details without affecting how users interact with the data.
50
Which of the following is NOT a type of database user?
Answer:
Network Administrator
A Network Administrator is responsible for maintaining the network infrastructure (hardware and software) that a database system may run on, but they are not considered a direct user of the DBMS itself. DBAs, application programmers, and end-users all interact with the database directly or indirectly.