Practice Questions

Duration: 6 min

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Module outline

  1. About the course: About the Course
  2. General Knowledge: Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, GK- Current Affairs, Indian Economy, Static General Knowledge, Environment, Evolution of Indian Banking (Banking & Financial Awareness)
  3. Mental Aptitude and Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Permutation and Combination, Number System, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Vocabulary, Profit and Loss, Arithmetic, Mental Ability, Percentage, Algebra, Mensuration and Geometry, Age Problems, Clock, Calendar, Verbal Analogy (Word Based Analogy), Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Analogy, Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Selection Decision Table (Decision Making), Cubes & Dices, Blood Relations, Venn Diagram, Logical Sequence Of Words, Inequality, Directions (Direction Test), Data Arrangement, Facts, Inference and Judgements, Syllogisms, Seating Arrangements, Ranking, Order and Sequence
  4. CS | Computer Fundamentals: Basics of COA, Number System, Number Representation, C Fundamentals, Algorithm Analysis, Input Output Organisation
  5. CS | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, SQL
  6. CS | Workplace productivity Tools: MS Office Applications, Keyboard Shortcuts
  7. CS | Computer Networks: Introduction to CN, Data Communication, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, Application Layer, Hardware Basics, Network Security
  8. CS | The Internet: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Web Publishing & Hosting, Server Side & Security, Emerging Technologies
  9. CS | Emerging Technologies: Artificial Intelligence, Emerging Tech Trends, Introduction to OS, Windows OS, Linux OS, Unix OS, JavaScript-Basics
  10. CS | Boolean algebra: Digital Systems & Boolean Basics, Boolean Expression, Boolean Minimization, Logic Gates & Hardware
  11. CS | Data Structures: Introduction to DS, Array, Stack, Queue
  12. CS | Cryptography: Society, Law & Ethics, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Electronic Data Interchange and E-Commerce, Physical Security and Cryptography Basics, Intrusion Detection Systems (IDS), Cyber Safety and Security
  13. UP Police Previous Year Papers:
  14. UP Police Full Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video features a lecture by Sanchit Jain from Knowledge Gate Educator, focusing on computer organization and disk access time calculations. The instructor presents a specific problem involving a disk with defined parameters: 512 bytes per sector, 400 sectors per track, 1000 tracks, and a rotation speed of 1500 RPM. The objective is to calculate the total time required to transfer a 1 MB file, given a seek time of 4 ms. The lecture systematically breaks down the total time into three components: Seek Time, Rotational Latency, and Transfer Time. Through step-by-step arithmetic and board work, the instructor demonstrates how to derive the final answer, providing a clear example of applying theoretical disk scheduling formulas to practical numerical problems.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video begins with the instructor introducing the problem statement displayed on the screen. He lists the given disk parameters: sector size of 512 bytes, 400 sectors per track, 1000 tracks, and a rotation speed of 1500 RPM. The file size is 1 MB, and the seek time is 4 ms. The instructor writes the formula for Total Time (T.T.T) on the whiteboard as the sum of Seek Time (S.T), Rotational Latency (R.L), and Transfer Time (T.T). He starts the calculation by determining the time for one full rotation of the disk. Using the RPM of 1500, he calculates 60 seconds divided by 1500, which equals 0.04 seconds or 40 milliseconds. He explains that the average rotational latency is half of the rotation time, so he divides 40 ms by 2 to get 20 ms for the rotational latency component.

  2. 2:00 – 5:00 02:00-05:00

    The instructor proceeds to calculate the Transfer Time (T.T). First, he determines the storage capacity of a single track by multiplying the number of sectors per track (400) by the sector size (512 bytes), resulting in 204,800 bytes per track. He then calculates the number of tracks required to store the 1 MB file. Representing 1 MB as 2^20 bytes, he divides the total file size by the bytes per track (2^20 / 204,800). This calculation yields approximately 5.12 tracks. Since the transfer time for one full track corresponds to one full rotation (40 ms), he multiplies the number of tracks by the rotation time. The equation becomes (2^20 / 204,800) * 40 ms. He performs the arithmetic to find that the transfer time is approximately 204.8 ms, which he writes as the third term in his total time equation.

  3. 5:00 – 5:38 05:00-05:38

    In the final segment, the instructor sums up all the calculated components to determine the final answer. He lists the values on the board: 4 ms for Seek Time, 20 ms for Rotational Latency, and 204.8 ms for Transfer Time. He performs the addition: 4 + 20 + 204.8. The sum results in 228.8 ms. He writes 228.8 ms on the board and underlines it to signify the final solution to the problem. The video concludes with this final numerical result displayed prominently, completing the step-by-step derivation of the disk access time.

The video provides a comprehensive guide to calculating disk access time by decomposing the process into seek, latency, and transfer phases. The instructor's methodical approach, starting from basic parameters and building up to the final sum, ensures clarity for students. By explicitly showing the conversion of RPM to milliseconds and the calculation of track capacity, the lecture reinforces key concepts in storage device performance analysis.

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