Practice Question

Duration: 17 min

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Inside: a video lesson and guided study material.

Module outline

  1. General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
  2. General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
  3. Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
  4. Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
  5. Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
  6. Programming & Data Structures: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, HTML Basics, OOPS with C++, Java, Object Oriented Technology
  7. Databases: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization
  8. Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  9. Theory of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  11. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
  12. Computer Networks: Introduction to CN, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware Basics, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
  13. Full Length Mock Tests:
  14. Sectional Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture is a practice question on CPU scheduling, specifically calculating the Average Turnaround Time (TAT) and Average Waiting Time (WT) using both Preemptive and Non-Preemptive Priority Scheduling. The instructor presents a table with four processes (P0 to P3) and their Arrival Times (AT), Burst Times (BT), and Priorities. The rule is that a lower priority number indicates a higher priority. The instructor first determines the execution order based on priority (P1, P3, P2, P0) and then constructs a Gantt chart for the Non-Preemptive case, showing process blocks P0, P1, P3, P2 with time marks 50, 70, 110, 210. He then transitions to the Preemptive case, where he updates the remaining burst times (e.g., 50→30, 20→0, 100→80) and constructs a new Gantt chart with boundary times 0, 30, 40, 60. Throughout the video, the instructor uses a whiteboard to draw the Gantt charts and a state diagram with 'Ready', 'Running', and 'Terminated' states to track the processes. The final timeline shows a Gantt chart with time marks 0, 20, 40, 60, 100, 180, 210, indicating the completion of the Preemptive scheduling calculation.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the practice question: 'Calculate the Average Turnaround Time (TAT) and Average Waiting Time (WT) using both Preemptive and Non-Preemptive Priority Scheduling.' A table is displayed with columns for P. No, AT, BT, Priority, CT, TAT = CT - AT, and WT = TAT - BT. The AT column lists 50, 20, 100, 40 (later corrected to 0, 20, 40, 60) and the Priority column lists 4, 1(h), 3, 2. The instructor points to the priority column and writes the sequence P1, P3, P2, P0, indicating the order of execution based on priority, with a note that a lower priority number indicates a higher priority.

  2. 2:00 – 5:00 02:00-05:00

    The instructor begins the Non-Preemptive Priority Scheduling calculation. The table lists P0 (0, 50, 4), P1 (20, 20, 1(h)), P2 (40, 100, 3), P3 (60, 40, 2). He draws a green Gantt-style bar at the bottom, filling in P0 then P1 with time marks 50 and 70. He also sketches a diagram at the right showing 'Ready', 'Running', and 'Terminated' circles to track the state of the processes. The instructor points to the 'Non-Preemptive' label circled in pink, emphasizing the current method.

  3. 5:00 – 10:00 05:00-10:00

    The Non-Preemptive Gantt chart is completed, showing process blocks P0, P1, P3, P2 with time marks 50, 70, 110, 210. The instructor uses a pink pen to gesture toward the green rectangle outline below the table. He then sketches three green ovals on the right labeled 'Ready', 'Running', and 'Ternate' (Terminated), with arrows connecting them. In the 'Running' oval, 'P1' appears, while the 'Ready' oval shows 'P0' and 'P1' crossed out in pink, indicating the transition of processes between states.

  4. 10:00 – 15:00 10:00-15:00

    The instructor transitions to the Preemptive Priority Scheduling calculation. The whiteboard table shows several BT entries crossed out and rewritten (50→30, 20→0, 100→80), representing the remaining burst times. A Gantt chart at the bottom extends from 'P0 | P1' to 'P0 | P1 | P2 | P3', with boundary times 0, 30, 40, 60 marked beneath it. Green hand-drawn ovals on the right are labeled 'Ready', 'Running', and 'Rem Data', each containing process names such as P0, P1, P2, to track the preemptive state changes.

  5. 15:00 – 16:33 15:00-16:33

    The Preemptive Gantt chart is progressively filled with process labels P0, P1, P2, P3 and time marks 0, 20, 40, 60, 100, 180, 210. Green handwritten notes on the right group processes under 'Ready', 'Running', and 'Time/Date' with several entries crossed out in red. The instructor stands before the digital whiteboard, completing the visualization of the Preemptive scheduling timeline, which allows for the final calculation of TAT and WT for both methods.

The lecture focuses on solving a CPU scheduling problem involving Preemptive and Non-Preemptive Priority Scheduling. The key concepts include the definition of Turnaround Time (TAT = CT - AT) and Waiting Time (WT = TAT - BT), and the rule that a lower priority number signifies higher priority. The instructor demonstrates the step-by-step process of determining the execution order based on priority and arrival time. For the Non-Preemptive case, the Gantt chart is built by running each process to completion once it starts, resulting in a timeline of P0, P1, P3, P2. For the Preemptive case, the instructor updates the remaining burst times and adjusts the Gantt chart to reflect preemptions, resulting in a more complex timeline with multiple state transitions. The use of state diagrams ('Ready', 'Running', 'Terminated') helps visualize the movement of processes through the system. This practice question is designed to help students understand the differences between preemptive and non-preemptive scheduling and how to calculate performance metrics for each.

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