What will be printed by: int x = 5; printf("%d", ++x + x++);?

The correct answer is B: 12. # Understanding Pre-increment and Post-increment Operators in C The key to solving this problem is understanding the difference between pre-increment (++x) and post-increment (x++) operators and their evaluation order. **Step 1: Evaluate Pre-increment (++x)** The pre-increment operator increases the

What happens when you use the strcpy() function without bounds checking?

The correct answer is B: It may cause buffer overflow if source string is longer than destination. strcpy() does not perform bounds checking. If the source string is longer than the destination buffer, it will write beyond the buffer boundary, causing a buffer overflow. This is a security vulnerability. Using strncpy() is safer.

Which data structure is best suited for implementing a priority queue?

The correct answer is C: Heap. A heap (binary heap) efficiently implements priority queues with O(log n) insertion and deletion of minimum/maximum elements.

Which algorithm is commonly used for sorting in most programming language standard libraries?

The correct answer is A: Introsort (Quicksort + Heapsort hybrid). Modern languages use Introsort which starts with Quicksort (O(n log n) avg) but switches to Heapsort (O(n log n) worst) to avoid worst-case scenarios.

What is the primary purpose of indexing in databases?

The correct answer is B: To speed up data retrieval operations. Indexes create a faster lookup structure similar to a book's index, enabling rapid data retrieval without full table scans.

Home

Home › Subjects › Computer Knowledge

Computer Knowledge

Programming, networking, database and OS questions

65 Q 2 Topics Take Mock Test

Difficulty: All Easy Medium Hard 1–10 of 65

Topics in Computer Knowledge

All C Programming 200 Database/SQL 100

Q.1 Hard Database/SQL

In a sharded database architecture deployed on cloud infrastructure, which of the following represents the most critical challenge that must be addressed?

A Shard key selection and distribution skew

B Implementing full-text search across shards

C Eliminating all network latency between shards

D Converting all queries to read-only operations

Correct Answer: A. Shard key selection and distribution skew

EXPLANATION

Shard key selection determines data distribution and performance. Poor shard key choices lead to hotspots, uneven load distribution, and performance degradation across the sharded cluster.

Test

Q.2 Hard Database/SQL

In AI/ML, what is the role of activation functions in neural networks?

A Encrypt network weights

B Introduce non-linearity enabling networks to learn complex patterns

C Increase training speed

D Reduce dataset size

Correct Answer: B. Introduce non-linearity enabling networks to learn complex patterns

EXPLANATION

Activation functions (ReLU, sigmoid, tanh) add non-linearity, allowing neural networks to approximate non-linear relationships.

Test

Q.3 Hard Database/SQL

What is the primary challenge of implementing ACID properties in distributed databases?

A Requires minimal network latency

B Network partitions, latency, and node failures make maintaining consistency difficult while ensuring availability

C Distributed systems automatically ensure ACID

D Only centralized databases can support ACID

Correct Answer: B. Network partitions, latency, and node failures make maintaining consistency difficult while ensuring availability

EXPLANATION

The CAP theorem shows it's impossible to guarantee all three: Consistency, Availability, and Partition tolerance simultaneously.

Test

Q.4 Hard Database/SQL

In distributed systems, what is a consensus algorithm primarily used for?

A Encrypting data

B Ensuring all nodes agree on a single value despite failures

C Compressing database files

D Load balancing across servers

Correct Answer: B. Ensuring all nodes agree on a single value despite failures

EXPLANATION

Consensus algorithms (like Raft, Paxos) enable distributed systems to reliably agree on state even with node failures.

Test

Q.5 Hard Database/SQL

In database normalization, what does the Boyce-Codd Normal Form (BCNF) address that 3NF might miss?

A Elimination of multivalued dependencies

B Removal of anomalies from composite candidate keys

C Prevention of circular foreign keys

D Ensuring data type consistency

Correct Answer: B. Removal of anomalies from composite candidate keys

EXPLANATION

BCNF handles edge cases in 3NF where anomalies can occur with composite candidate keys where determinants are not candidate keys themselves.

Test

Q.6 Hard Database/SQL

In a B-tree of order m, what is the maximum number of keys that a non-root node can contain?

A m-1

B m

C 2m-1

D 2m

Correct Answer: C. 2m-1

EXPLANATION

A B-tree of order m can have at most 2m-1 keys in any node and minimum m-1 keys in non-root nodes.

Test

Q.7 Hard Database/SQL

What is the primary advantage of using GraphQL over traditional REST APIs in modern application architecture?

A GraphQL always provides better performance

B GraphQL allows clients to request only required data fields, reducing over-fetching

C GraphQL eliminates the need for databases

D REST APIs are completely replaced by GraphQL

Correct Answer: B. GraphQL allows clients to request only required data fields, reducing over-fetching

EXPLANATION

GraphQL's query language enables clients to specify exact data requirements, eliminating over-fetching and under-fetching issues common in REST.

Test

Q.8 Hard Database/SQL

In cybersecurity, what is SQL injection and why is it a critical vulnerability in 2024?

A Injecting SQL commands to execute unauthorized database operations

B A performance optimization technique

C A method to improve database security

D An outdated vulnerability no longer relevant

Correct Answer: A. Injecting SQL commands to execute unauthorized database operations

EXPLANATION

SQL injection allows attackers to insert malicious SQL code through application inputs, remaining a critical OWASP Top 10 vulnerability despite awareness.

Test

Q.9 Hard Database/SQL

Which of the following best describes a distributed transaction and its challenges in microservices architecture?

A Transactions that execute only on primary databases

B Transactions spanning multiple services requiring coordination and handling failures

C Transactions that cannot be executed in microservices

D Local transactions that never require coordination

Correct Answer: B. Transactions spanning multiple services requiring coordination and handling failures

EXPLANATION

Distributed transactions in microservices require mechanisms like Saga pattern or Two-Phase Commit to maintain consistency across services.

Test

Q.10 Hard Database/SQL

In database replication, what is the primary difference between synchronous and asynchronous replication?

A Synchronous is always faster

B Asynchronous waits for replica confirmation; Synchronous does not

C Synchronous waits for replica confirmation; Asynchronous does not

D Both have identical performance characteristics

Correct Answer: C. Synchronous waits for replica confirmation; Asynchronous does not

EXPLANATION

Synchronous replication waits for replicas to acknowledge writes (safer but slower), while asynchronous replication doesn't wait (faster but less safe).

Test

1 2 3…7

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

Computer Knowledge

About Computer Knowledge Practice on iGET

Why prepare with iGET?

How to use this page effectively