Gate 2015

Duration: 4 min

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Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Paper-1 & 2 | Basic Numeracy: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Mensuration and Geometry, Age Problems, Arithmetic, Statistics, Probability, Profit and Loss, Simple Interest and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, Powers and Exponents (Surds and Indices), Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy
  3. Paper-1 & 2 | Data Interpretation: Data Interpretation
  4. Paper-1 & 2 | General Mental Ability: Mental Ability, RSSB Specific Videos - Mental Ability
  5. Paper-1 & 2 | Logical Reasoning and Analytical Ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Analogy, Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Arrangement, Logical Sequence Of Words, Crypt Arithmetic
  6. Paper-1 & 2 | Decision Making and Problem Solving: Selection Decision Table (Decision Making)
  7. Paper-1 | General Science: Physics, Biology, Chemistry, RSSB Specific Videos
  8. Paper-1 | General Awareness: State Wise GK, GK- Current Affairs
  9. Paper-2 | Fundamentals of Computer: Basics of COA, Number System, Floating Point Rep, Number Representation
  10. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits
  11. Paper-2 | Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Linux OS, Distributed Systems
  12. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Relational Calculus, File Organization & Indexing, Transaction Management, Concurrency Control
  13. Paper-2 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  15. Paper 2 | Oops, C++, Java: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  16. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  17. Paper 2 | Emerging Trends and AI: Emerging Tech Trends, Artificial Intelligence
  18. Paper-2 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Advanced Algorithms
  19. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, 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, Network Security, Ethical Hacking
  20. Paper-2 I Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  21. Paper-2 | Computer Organization and Architecture: Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations
  22. Paper-2 | Web Development: JavaScript-Basics, HTML Basics, CSS, XML
  23. Pedagogy: Child Development, Concept of Pedagogy, Psychology, Theories, Inclusive Education, Experiential Pedagogy, Curriculum Framework & Reforms, National Education Policy (NEP) 2020
  24. Live Sessions: RSSB Live Sessions
  25. RSSB Paper 1 - Full Mock Tests:
  26. RSSB Paper 2 - Full Mock Tests:
  27. SCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video presents a solution to a GATE 2015 problem concerning disk scheduling algorithms, specifically the optimized C-SCAN algorithm. The instructor begins by reading the problem statement, which involves a disk with tracks 0-255, a current head position at track 45 moving in the positive direction, and a queue of requests: 40, 67, 11, 240, 87. The goal is to determine the service order and the total seek distance. He draws a number line to visualize the tracks and marks the current head position and the request locations. He explains that C-SCAN moves in one direction (positive) servicing requests until the end of the disk, then jumps to the beginning and continues in the same direction. He identifies the requests in the positive direction (67, 87, 240) and those in the negative direction (11, 40) which will be serviced after the jump to track 0.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the problem statement, highlighting the key parameters: head at track 45, moving positive, requests {40, 67, 11, 240, 87}. He draws a horizontal line representing the disk tracks from 0 to 255. He marks the current head position at 45. He then plots the request tracks on the line: 11, 40, 67, 87, and 240. He explains the C-SCAN logic: the head moves towards the positive direction, servicing requests 67, 87, and 240. He notes that the head will continue to the end of the disk (track 255) before jumping to the start (track 0). He then identifies the remaining requests (11, 40) that will be serviced after the jump. He begins writing the calculation for the total seek distance on the board, starting with the distance from the current head to the end of the disk. He writes `(255 - 45)`.

  2. 2:00 – 4:03 02:00-04:03

    The instructor continues the calculation for the total seek distance. He writes `(255 - 45)`, representing the distance from the current head to the end of the disk. He then adds `255` to this value, representing the distance of the jump from the end (255) to the start (0). Finally, he adds `40`, representing the distance from the start (0) to the last serviced request (40). He sums these values: 210 + 255 + 40 = 505. He circles the final answer 505 and selects option (C) as the correct choice. He briefly confirms the service order as 67, 87, 240, 11, 40, although the primary focus of this segment is the numerical calculation of the seek distance. He explicitly writes the sum `210 + 255 + 40` and the result `505` on the board, circling it to indicate the final answer.

The lecture effectively demonstrates how to apply the C-SCAN disk scheduling algorithm to a specific problem. By visualizing the track layout and the head movement, the instructor clarifies the service order and the calculation of seek distance. The key takeaway is the specific method for calculating C-SCAN seek distance, which includes the full traversal to the end, the jump to the start, and the traversal to the last request, resulting in a total distance of 505 units. This approach highlights the importance of understanding the specific variations of disk scheduling algorithms for exam purposes.

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