Practice Questions

Duration: 4 min

This video lesson is available to enrolled students.

Return to /learn/MPPSC-ASSISTANT-PROFESSOR-COMPUTER-SCIENCE-PAPER-2/digital-computer-organization-and-architecture/input-output-organisation/disk-access-time-performance/asset-practice-questions-1955 after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Paper 1 | General Studies: State Wise GK
  3. Paper 1 | Information and Communication Technology: Role of Internet and Web Services, Security in Mobile and Wireless Computing
  4. Paper 1 | Current Affairs: GK- Current Affairs
  5. Paper 2 | Discrete Mathematical Structure: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Probability
  6. Paper 2 | Digital Computer Organization And Architecture: Number System, Number Representation, Sequential Circuits, Combinational Circuit, Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer
  7. Paper 2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  8. Paper 2 | Programming Languages & Object-Oriented Programming Concepts: Java, OOPS with C++, Java Fundamentals, Array, String, IO & References
  9. 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
  10. Paper 2 | Data Structure And Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Advanced Algorithms
  11. Paper 2 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS
  12. Paper 2 | 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
  13. Paper 2 | 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
  14. 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, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization, Enhanced Data Models
  15. Paper 2 | Computer Network And Information Security: Introduction to CN, Data Communication, Application Layer, Hardware basics, Cyber Threats and Malware Attacks, Network Security, 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
  16. Paper 2 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  17. Paper 2 | Current Trends & Technologies: Emerging Tech Trends, Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Planning, Multi Agent Systems, Fuzzy Sets, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms, Artificial Intelligence, Data Warehousing & Mining, Electronic Data Interchange and E-Commerce, Terms & Abbreviations
  18. Paper 2 | Full Length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The lecture focuses on calculating the total time required to transfer a file stored on a disk, specifically comparing contiguous and non-contiguous allocation strategies. The problem provides specific disk parameters: 8 sectors per track, 512 bytes per sector, a rotation speed of 3000 rpm, and an average seek time of 15ms. The file size is defined as requiring 8 sectors. The instructor systematically breaks down the components of disk access time: Seek Time (ST), Rotational Latency (RL), and Transfer Time (TT). He demonstrates the calculation for non-contiguous allocation, where each sector requires a separate seek and latency operation, contrasting it with the efficiency of contiguous allocation where data is stored sequentially.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the problem statement visible on the screen, which asks for the total time to transfer a file requiring 8 sectors. He begins by analyzing part (b) Non-contiguous allocation. He writes the general formula for total time as the sum of Seek Time (ST), Rotational Latency (RL), and Transfer Time (TT). He then calculates the Rotational Latency based on the 3000 rpm speed. He converts rpm to rotations per second (3000/60 = 50) and determines the time for one full rotation (1000ms/50 = 20ms). Consequently, the average rotational latency is half of that, which he writes as 10ms on the board. He explicitly writes "10 ms" under the RL term in his formula.

  2. 2:00 – 3:36 02:00-03:36

    Continuing with the non-contiguous allocation calculation, the instructor explains that since the file requires 8 sectors and they are non-contiguous, the disk head must seek and wait for rotation for each sector individually. He writes the expression 8 (15ms + 10ms), representing 8 times the sum of seek time (15ms) and rotational latency (10ms). He then calculates the Transfer Time (TT). Since there are 8 sectors per track and the file is 8 sectors, the transfer time equals the time for one full rotation, which is 20ms. He writes 8/8 * 20ms = 20ms. Finally, he sums the components: 8 * 25ms + 20ms, resulting in a total time of 220ms. He writes "220ms" as the final answer on the board.

The lesson effectively demonstrates how disk allocation strategies impact performance. By calculating the time for non-contiguous allocation, the instructor highlights the overhead of multiple seek and latency operations. The final result of 220ms serves as a concrete example of the inefficiency compared to contiguous allocation, where the seek and latency would only occur once. This reinforces the importance of file system design in optimizing I/O operations.

Loading lesson…