Gate 2015

Duration: 4 min

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Inside: a video lesson and guided study material.

Module outline

  1. Quantitative Aptitude: Number System, Divisibility Rules, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Mixture and Alligation, Partnership, Age Problems, Time and Work, Pipe and Cistern, Speed Time and Distance, Algebra, Arithmetic, Data Interpretation, Sequence and Series (Series), Logarithm, Powers and Exponents (Surds and Indices), Permutation and Combination, Probability, Speed Mathematics and Basic Mathematics, Trigonometry
  2. Logical Reasoning: Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Seating Arrangements, Puzzle Solving (Puzzles), Data Arrangement, Syllogisms, Inequality, Data Sufficiency, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Venn Diagram, Logical Sequence Of Words, Calendar, Clock, Cubes & Dices, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning)
  3. Verbal Ability: Noun, Pronoun, Adjectives, Verb, Adverb, Tenses, Subject Verb Agreement (Verb Noun Agreement), Articles, Preposition, Conjunction, Modals, Determiner, Vocabulary, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Construction
  4. Data Structures (Domain Test): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  5. Algorithms (Domain Test): Algorithm Analysis, Sorting Algorithms, Time Complexity Analysis, Greedy Algorithms
  6. OOPs (Domain Test): Object Oriented Programming (OOPS)
  7. DBMS (Domain Test): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  8. SQL (Domain Test): SQL
  9. Operating Systems (Domain Test): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  10. Computer Networks (Domain Test): Introduction to CN, Data Communication, 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, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
  11. Coding: Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir
  12. Written English Test: English Writing Ability
  13. Psychometric Test: Behavioral Assessment (Behavioral Competency Profiling) (Psychometric Test)
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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