What does the sizeof() operator return in C?

The correct answer is B: The memory size in bytes of a data type or variable. The sizeof() operator returns the size in bytes of a data type or variable. For example, sizeof(int) typically returns 4 on most 32-bit systems.

Which normal form eliminates transitive dependencies in a database table?

The correct answer is A: Third Normal Form (3NF). 3NF removes transitive dependencies where a non-key attribute depends on another non-key attribute. BCNF is stricter but 3NF is the standard answer for eliminating transitive dependencies.

Which of the following best describes microservices architecture?

The correct answer is A: Breaking applications into small, independently deployable services. Microservices decompose applications into loosely-coupled, independently deployable services. This enables scalability, flexibility, and technology diversity.

Consider a pointer ptr pointing to an integer array. What does ptr[2] represent?

The correct answer is B: The value of the third element. ptr[2] is equivalent to *(ptr+2), which dereferences the pointer and returns the value at the third element (index 2).

In C, what is the purpose of the #define directive?

The correct answer is B: To define macros or constants. #define is a preprocessor directive used to define symbolic constants (macros) and performs text substitution before compilation.

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All C Programming 200 Database/SQL 100

Q.21 Easy Database/SQL

In cybersecurity, what is the primary purpose of a firewall?

A Control incoming and outgoing network traffic based on rules

B Encrypt all data transmitted

C Detect viruses and malware

D Manage user authentication

Correct Answer: A. Control incoming and outgoing network traffic based on rules

EXPLANATION

Firewalls filter traffic based on security policies. While they provide protection, encryption is separate, antivirus is different, and authentication is handled by other systems.

Test

Q.22 Easy Database/SQL

In cloud computing, what does IaaS stand for?

A Infrastructure as a Service

B Integration as a Service

C Intelligent as a Service

D Internal as a Service

Correct Answer: A. Infrastructure as a Service

EXPLANATION

IaaS provides virtualized computing resources over the internet (AWS EC2, Azure VMs). PaaS and SaaS are higher-level abstractions.

Test

Q.23 Easy Database/SQL

What is the time complexity of searching in a balanced binary search tree?

A O(log n)

B O(n)

C O(n log n)

D O(1)

Correct Answer: A. O(log n)

EXPLANATION

Balanced BSTs (AVL, Red-Black) maintain O(log n) search time by keeping height logarithmic. Unbalanced trees degrade to O(n) in worst case.

Test

Q.24 Easy Database/SQL

In SQL, which JOIN returns only matching records from both tables?

A INNER JOIN

B LEFT JOIN

C FULL OUTER JOIN

D CROSS JOIN

Correct Answer: A. INNER JOIN

EXPLANATION

INNER JOIN returns only rows with matching values in both tables. LEFT JOIN includes unmatched left table rows, FULL OUTER JOIN includes all rows, and CROSS JOIN produces Cartesian product.

Test

Q.25 Easy Database/SQL

What does ACID stand for in database transactions?

A Atomicity, Consistency, Isolation, Durability

B Availability, Consistency, Integrity, Distribution

C Atomicity, Concurrency, Isolation, Data

D Authorization, Consistency, Integration, Durability

Correct Answer: A. Atomicity, Consistency, Isolation, Durability

EXPLANATION

ACID properties ensure reliable database transactions: Atomicity (all-or-nothing), Consistency (valid state), Isolation (concurrent independence), and Durability (permanent storage).

Test

Q.26 Easy Database/SQL

Which of the following is a non-relational database designed for handling unstructured data at scale?

A MongoDB

B PostgreSQL

C Oracle Database

D MySQL

Correct Answer: A. MongoDB

EXPLANATION

MongoDB is a NoSQL document database that handles unstructured and semi-structured data efficiently, unlike relational databases like PostgreSQL, Oracle, and MySQL.

Test

Q.27 Easy Database/SQL

What does the acronym ACID stand for in database transactions?

A Atomicity, Consistency, Isolation, Durability

B Access, Control, Integration, Distribution

C Accuracy, Completeness, Integrity, Detection

D Authorization, Concurrency, Indexing, Duration

Correct Answer: A. Atomicity, Consistency, Isolation, Durability

EXPLANATION

ACID properties ensure reliable database transactions: Atomicity (all-or-nothing), Consistency (valid state), Isolation (concurrent independence), Durability (permanent storage).

Test

Q.28 Easy Database/SQL

Which of the following is NOT a characteristic of a relational database?

A Uses tables with rows and columns

B Enforces ACID properties

C Supports unstructured data storage by default

D Uses primary keys for unique identification

Correct Answer: C. Supports unstructured data storage by default

EXPLANATION

Relational databases store structured data in tables. Unstructured data is typically stored in NoSQL or document databases.

Test

Q.29 Easy Database/SQL

In a hash table, what is the primary cause of collision?

A Two different keys hashing to the same index

B Insufficient memory allocation

C Poor sorting algorithm

D Network latency issues

Correct Answer: A. Two different keys hashing to the same index

EXPLANATION

Hash collisions occur when two different keys hash to the same table index. Resolution techniques include chaining and open addressing.

Test

Q.30 Easy Database/SQL

Which SQL command is used to remove a table structure along with its data?

A DELETE

B DROP

C TRUNCATE

D REMOVE

Correct Answer: B. DROP

EXPLANATION

DROP removes the entire table structure and data. DELETE removes only data. TRUNCATE removes data but is faster than DELETE.

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