Showing 21–30 of 150 questions
What is the normal form that ensures no partial dependencies exist in a relation?
A
Third Normal Form (3NF)
B
Boyce-Codd Normal Form (BCNF)
C
Second Normal Form (2NF)
D
First Normal Form (1NF)
Correct Answer:
C. Second Normal Form (2NF)
EXPLANATION
2NF eliminates partial dependencies where non-key attributes depend on part of a composite key. 3NF further eliminates transitive dependencies.
What is the time complexity of searching an element in a balanced Binary Search Tree?
A
O(n)
B
O(n log n)
C
O(log n)
D
O(1)
Correct Answer:
C. O(log n)
EXPLANATION
A balanced BST maintains O(log n) search complexity by keeping the tree height logarithmic relative to node count.
Which encryption standard is currently recommended for securing data in transit over networks?
A
DES
B
MD5
C
TLS 1.3
D
SHA-1
Correct Answer:
C. TLS 1.3
EXPLANATION
TLS 1.3 is the latest, most secure protocol standard for encrypting data in transit, replacing older protocols like SSL and TLS 1.2.
In machine learning, what is a confusion matrix primarily used for?
A
To train neural networks
B
To evaluate classification model performance
C
To normalize feature scaling
D
To generate random datasets
Correct Answer:
B. To evaluate classification model performance
EXPLANATION
A confusion matrix shows True Positives, True Negatives, False Positives, and False Negatives, enabling comprehensive evaluation of classification accuracy.
What is the primary benefit of containerization technology like Docker in modern application deployment?
A
Reduces application performance
B
Ensures consistency between development and production environments
C
Eliminates the need for databases
D
Automatically handles all security patches
Correct Answer:
B. Ensures consistency between development and production environments
EXPLANATION
Docker containers package applications with dependencies, ensuring identical execution across different environments.
In cloud computing, what does the term 'eventual consistency' refer to?
A
Data is immediately consistent across all nodes
B
Data will become consistent across distributed systems after some time
C
Consistency checks are performed eventually
D
Cloud systems never achieve consistency
Correct Answer:
B. Data will become consistent across distributed systems after some time
EXPLANATION
Eventual consistency in cloud systems means that data replicas will converge to the same state after all updates have propagated.
Which data structure is most efficient for implementing a LRU (Least Recently Used) cache?
A
Array
B
Hash Map + Doubly Linked List
C
Binary Search Tree
D
Queue only
Correct Answer:
B. Hash Map + Doubly Linked List
EXPLANATION
Hash Map provides O(1) lookup while Doubly Linked List maintains insertion order and allows O(1) removal/reordering.
In SQL, what is the difference between HAVING and WHERE clauses?
A
Both serve identical purposes
B
WHERE filters rows before grouping; HAVING filters groups after aggregation
C
HAVING is used for individual row filtering
D
WHERE can only be used with JOIN operations
Correct Answer:
B. WHERE filters rows before grouping; HAVING filters groups after aggregation
EXPLANATION
WHERE clause filters individual rows before GROUP BY, while HAVING filters aggregated groups after GROUP BY.
What does CAP theorem state about distributed database systems?
A
All three properties can be achieved simultaneously
B
Only two of Consistency, Availability, and Partition tolerance can be guaranteed
C
Consistency is always sacrificed first
D
Partition tolerance is optional in modern systems
Correct Answer:
B. Only two of Consistency, Availability, and Partition tolerance can be guaranteed
EXPLANATION
CAP theorem proves that distributed systems can guarantee at most 2 of 3 properties: Consistency, Availability, and Partition tolerance.
Which of the following is NOT a characteristic of relational databases?
A
ACID compliance
B
Flexible schema
C
Structured data storage
D
Data integrity constraints
Correct Answer:
B. Flexible schema
EXPLANATION
Relational databases have fixed schemas. Flexible schemas are a characteristic of NoSQL databases like MongoDB.
