Welcome to your ISRO SC Mock Test 1 Which data structure naturally models function calls and local variables in recursion? Queue Stack Heap Linked List None Comment Which TCP mechanism helps control congestion by reducing the sending rate when packet loss is detected? Flow control (window size) Slow start and congestion avoidance (e.g., TCP Tahoe/Reno) Checksum Segmentation None Comment Which graph algorithm is used to compute a Minimum Spanning Tree (MST)? Dijkstra Kruskal Bellman-Ford Floyd–Warshall None Comment Which CPU scheduling algorithm can cause starvation for lower-priority processes? First Come First Serve Shortest Job First Round Robin Priority Scheduling None Comment Which property does 'D' stand for in ACID transactions? Durability Deadlock Duplicate Dependency None Comment What is the worst-case time complexity of Heap Sort for n elements? O(n) O(n log n) O(n^2) O(log n) None Comment Which query finds the number of students in each department in SQL? SELECT dept, COUNT(*) FROM students; SELECT dept FROM students GROUP BY COUNT(*); SELECT COUNT(*), dept FROM students GROUP BY dept; SELECT dept, COUNT(*) FROM students GROUP BY dept; None Comment Which isolation level prevents dirty reads but may allow non-repeatable reads? Read Uncommitted Read Committed Repeatable Read Serializable None Comment Which algorithm is used for topological sorting of a DAG using in-degree counting? Kahn's algorithm Tarjan's strongly connected components Dijkstra's algorithm Prim's algorithm None Comment Given IPv4 network mask /24, the maximum number of usable hosts in that subnet is: 256 254 255 252 None Comment Which device primarily operates at the Data Link layer and forwards frames based on MAC addresses? Hub Switch Router Gateway None Comment Which normal form removes transitive dependencies in relational schemas? 1NF 2NF 3NF BCNF None Comment Which cryptographic hash property ensures it is computationally infeasible to find two messages producing same hash? Pre-image resistance Second pre-image resistance Collision resistance Avalanche effect None Comment Which transport-layer protocol provides reliability, congestion control and flow control? UDP IP TCP ICMP None Comment Which data structure supports efficient predecessor/successor queries (floor/ceiling) in O(log n)? Hash table Binary Search Tree (balanced, e.g., AVL/Red-Black) Queue Stack None Comment Which wireless technology uses OFDM and operates in 2.4/5 GHz for local area networking? Bluetooth Zigbee Wi-Fi (IEEE 802.11) LoRa None Comment In computer networks, ARP is used to map which pair? IP address to domain name IP address to MAC address Port number to process MAC address to routing table None Comment Which of these is NOT a context-free language recognizer model? Pushdown Automaton Deterministic Pushdown Automaton Finite Automaton Context-free grammar None Comment Which graph representation is most memory-efficient for sparse graphs with V vertices and E edges? Adjacency matrix Adjacency list Incidence matrix Edge list with matrix None Comment Average-case time complexity of hash table search (with good hashing and load factor) is: O(1) O(log n) O(n) O(n log n) None Comment Which tree rotation is required to fix an AVL tree after insertion causing left-right imbalance (LR)? Single right rotation Single left rotation Left-Right double rotation (LR) Right-Left double rotation (RL) None Comment Which statement about NP-complete problems is true? They are solvable in polynomial time Every NP problem reduces to any NP-complete problem in polynomial time They have exponential space requirement They are identical to P problems None Comment Which memory mapping technique allows direct mapping of any block to only one cache line? Fully associative Direct mapped Set associative Virtual memory mapping None Comment Which concurrent programming primitive allows mutual exclusion and can be binary or counting? Semaphore Barrier Monitor Message Queue None Comment Which of the following sorting algorithms has worst-case O(n log n) and is in-place but not stable? Merge Sort Heap Sort Insertion Sort Bubble Sort None Comment Which algorithmic paradigm does 'Knapsack (0/1) dynamic programming' belong to? Greedy Divide and Conquer Dynamic Programming Backtracking None Comment Which algorithm is used to find the shortest path in an unweighted graph from a source vertex? Dijkstra's algorithm Breadth-First Search (BFS) Bellman-Ford algorithm Floyd–Warshall None Comment Which sorting algorithm is stable by default? Quick Sort Merge Sort Heap Sort Selection Sort None Comment Which technique is used to resolve collisions in open addressing hash tables? Chaining Linear probing Separate chaining with list B-tree None Comment Which complexity describes QuickSort average-case performance? O(n^2) O(n log n) O(n) O(log n) None Comment What is the purpose of a file system journal (write-ahead log)? Improve CPU utilization Keep backup of files on remote server Provide durability and aid crash recovery by logging changes before commit Increase file fragmentation None Comment Which operation on a binary heap takes O(log n) time? Access min/max without removal Insert and extract (remove root) Build heap from array Check size None Comment Which technique is used by LZW compression (as used in GIF) broadly? Entropy coding (Huffman) Dictionary-based compression Run-length encoding only Delta encoding None Comment In relational database, which index type is typically used for range queries and ordered retrieval? Hash index B-tree index Bitmap index No index None Comment Which OSI layer is responsible for logical addressing and routing? Physical Data Link Network Transport None Comment Using a binary heap, Dijkstra's algorithm complexity (in terms of E edges, V vertices) is approximately: O(V^2) O(E + V log V) O(E log V) O(V log V) None Comment Which structure is used to implement recursion elimination for tail recursion? Stack Heap Tail-call optimization (transform into loop) Queue None Comment Which of the following is a stable hashing method useful for distributed hash tables? Separate chaining Consistent hashing Linear probing Quadratic probing None Comment Which of the following best describes virtual memory? Physical memory only Secondary storage only Technique to make a large logical address space by using disk as extension of RAM Cache only None Comment Which complexity class contains problems solvable in polynomial time by a deterministic Turing machine? NP P EXP PSPACE None Comment Which RAID level stripes data and provides no redundancy (single stripe across disks)? RAID 0 RAID 1 RAID 5 RAID 6 None Comment Which statement best describes a semaphore's P() and V() operations? P() increments, V() decrements P() decrements (wait), V() increments (signal) Both are atomic swaps They are only for memory allocation None Comment Which algorithm is used to detect cycles in directed graph efficiently? Topological sort attempt using DFS with visited + recursion stack check Dijkstra Kruskal Prim None Comment Which data structure is ideal for implementing breadth-first search queue operations? Stack Queue Priority Queue Hash Table None Comment Which page replacement algorithm is provably optimal (but not implementable in practice)? LRU (Least Recently Used) FIFO (First In First Out) Optimal (Belady's algorithm) Clock algorithm None Comment Which data structure is best suited to implement LRU cache efficiently (O(1) get and put)? Array Stack Hash map + Doubly linked list Binary search tree None Comment Which of the following is true about ACID 'Isolation' levels? Serializable is the strongest isolation level Read Uncommitted prevents phantom reads Repeatable Read prevents dirty reads Read Committed prevents phantom reads None Comment Which of the following is NOT part of lexical analysis in compilers? Tokenization Removing comments and whitespace Parsing into AST Recognizing lexemes None Comment Which of these SQL statements creates a new table copying schema and data from another table? CREATE TABLE new AS SELECT * FROM old; INSERT INTO new SELECT * FROM old; ALTER TABLE new ADD LIKE old; SELECT INTO new FROM old; None Comment Which data structure supports efficient range minimum queries (RMQ) with O(1) query after O(n log n) preprocessing? Segment Tree Fenwick Tree Sparse Table Binary Indexed Tree None Comment Which of the following is true about B-tree indexes in databases? They are useful for exact-match only They maintain sorted order and support range queries They are always in-memory only They are unsuited for disk storage None Comment Which method is used to detect and recover from database deadlocks commonly? Wait-die scheme Wound-wait scheme Timeout-based abort or deadlock detection with periodic wait-for graph Two-phase commit None Comment Which SQL clause removes duplicate rows from result set? GROUP BY DISTINCT UNIQUE HAVING None Comment In TCP three-way handshake, the sequence of flags is: SYN → SYN-ACK → ACK SYN-ACK → SYN → ACK ACK → SYN → SYN-ACK SYN → ACK → SYN-ACK None Comment Which of the following is a mutual exclusion solution for two processes using only shared variables (software)? Banker's algorithm Peterson's algorithm Dijkstra's algorithm (for resource allocation) FIFO scheduling None Comment Which traversal of a Binary Search Tree (BST) returns keys in non-decreasing order? Preorder Inorder Postorder Level order None Comment Which OS deadlock condition is described by 'circular wait'? Mutual exclusion Hold and wait No preemption Circular chain of processes waiting for resources None Comment Which file organization uses a separate index structure to support fast lookup without reordering records? Heap file organization Indexed sequential file Sequential file only Hashed file without index None Comment Which is a non-polynomial problem class where solutions can be verified in polynomial time? P NP PSPACE LOGSPACE None Comment Which of the following is true about 'Serializable' isolation level? It allows phantom reads It is equivalent to executing transactions in some serial order It is weaker than Repeatable Read It allows dirty reads None Comment Which network routing algorithm is 'link-state' type? Distance Vector (Bellman-Ford) OSPF (Open Shortest Path First) RIP (Routing Information Protocol) Static routing None Comment Which protocol uses port numbers 80 and 443 commonly? FTP SMTP HTTP/HTTPS DNS None Comment Which flip-flop is edge-triggered and can be used to build registers (stores single bit synchronized to clock)? Latch D flip-flop Combinational gate Multiplexer None Comment Which addressing mode yields an operand by adding an immediate constant to a register value (e.g., R1 + offset)? Immediate addressing Register addressing Base+offset (displacement) addressing Direct addressing None Comment Which algorithm finds strongly connected components in a directed graph using a single DFS pass and a stack? Kahn's algorithm Kosaraju's algorithm Tarjan's algorithm Prim's algorithm None Comment What is the main idea of divide and conquer paradigm? Use greedy choice at each step Solve using dynamic programming memoization only Divide problem into subproblems, solve recursively and combine Brute force search all possibilities None Comment Which of the following hashing collision resolution methods is NOT open addressing? Linear probing Quadratic probing Double hashing Separate chaining with linked lists None Comment Which of the following is true for functional dependencies in relational schema? A→B and B→C implies A→C (transitivity) A→B implies B→A Functional dependencies are irrelevant to normalization No FD can be derived from others None Comment Which of these is a non-preemptive scheduling policy? Round Robin Shortest Remaining Time First First Come First Serve Preemptive Priority None Comment Which cryptosystem uses the same key for encryption and decryption? RSA Diffie-Hellman Symmetric key cryptography (AES) ElGamal None Comment Which scheduling algorithm gives minimum average waiting time for a set of processes but may be unfair to long jobs? Round Robin Shortest Job First (SJF) First Come First Serve (FCFS) Priority scheduling None Comment Which instruction-level hazard occurs when an instruction depends on the result of a previous instruction still in pipeline? Structural hazard Data hazard Control hazard Memory hazard None Comment Which TCP flag is set when a segment contains urgent data? ACK RST URG PSH None Comment Which instruction is responsible for transferring control in assembly (jump)? MOV ADD JMP CMP None Comment Time's upTime is Up!
