BSCS Cheat Sheet 2026

The 30 highest-yield BSCS facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What components are encompassed within the DBMS subsystem? → All of the above
2. The concept of 'copy-on-write' (COW) after fork() means that: → Child and parent share pages until one of them writes, triggering a private copy
3. In the context of disk scheduling, what does LOOK differ from SCAN? → LOOK reverses direction at the last request rather than at the disk end
4. When is it necessary for a computer to possess an IP address? → Connecting to a Wi-Fi hotspot
5. Which concurrency control technique uses timestamps to order transactions? → Timestamp ordering protocol
6. Which search algorithm uses a heuristic function h(n) to estimate the cost from node n to the goal and expands the node with the lowest f(n) = g(n) + h(n)? → A* search
7. What is another term that can refer to a home computer network → LAN
8. Networks facilitate the sharing of files among computers. → TRUE
9. In computer vision, what is the purpose of a convolutional layer in a CNN? → To apply learned filters across the input to detect local spatial patterns
10. both a) and b) are always true When a separate-chaining hash table possesses a load factor λ of 5, what value does the average chain length assume? → 5
11. What does ARP (Address Resolution Protocol) map? → IP addresses to MAC addresses
12. Which topology connects every node directly to every other node, providing the highest redundancy? → Full-mesh
13. What is the difference between a permutation and a combination? → Permutations count ordered arrangements; combinations count unordered selections
14. Which page replacement algorithm suffers from Belady's anomaly, where adding more frames can increase page faults? → FIFO (First-In, First-Out)
15. What is a phantom read in database transactions? → A new row appearing in repeated queries due to another transaction's insert
16. What is the purpose of the program counter (PC) register? → Holds the memory address of the next instruction
17. What does IEEE 754 define? → Floating-point arithmetic and number representation
18. A network forms when a single device is linked to another. → FALSE
19. What are the drawbacks of networks? → Viruses
20. Which dimensionality reduction technique finds principal components by maximizing variance in the projected data? → Principal Component Analysis (PCA)
21. Which division of machine learning draws inspiration from the intricate network of neurons in the human brain? → Deep Learning
22. What capability does the operating system offer as a platform? → Applications
23. What problem can arise if a low-priority process holds a resource needed by a high-priority process? → Priority inversion
24. In a multi-level feedback queue (MLFQ) scheduler, a process that uses its entire time quantum is typically: → Moved to a lower-priority queue
25. Which scheduling metric measures the total time from process submission to completion? → Turnaround time
26. In the context of Ethernet, what is the maximum length of a standard UTP Cat5e cable segment before signal degradation requires a repeater? → 100 meters
27. In the context of AI, what is the main emphasis of Cognitive Science? → Studying the human mind using AI techniques
28. In support vector machines (SVM), what is the role of the kernel function? → To map data into a higher-dimensional feature space where it becomes linearly separable
29. What does the 'exploration vs. exploitation' dilemma refer to in reinforcement learning? → Balancing trying new actions to gather information versus using known high-reward actions
30. Which design pattern ensures only one instance of a class exists? → Singleton