DEMux_practice_question

Duration: 2 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 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits
  10. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Calculus, Relational Algebra, SQL, NoSQL
  11. Paper-2 | Data Structures & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Algorithm Analysis, Sorting Algorithms, Intro to Compilers, Hashing
  12. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, Data Link Layer - Ethernet, DLL: Error Control, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Application Layer, Hardware basics, Network Security, Ethical Hacking
  13. Paper-2 | Operating Systems: Introduction to OS, Process Management, Memory Management, File Management, Deadlock
  14. Paper-2 | Computer Organization and Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer, Number System, Number Representation
  15. Paper 2 | System Analysis and Design: Fundamentals of Systems and Information Systems, Fundamentals of Software Engineering, SDLC and Development Approaches, Software Documentation and Software Requirements Specification (SRS), SDD and Quality Assurance, Security, Risk Management & Maintenance, Software Testing
  16. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Paper 2 | OOPS , C++ , JAVA: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  18. 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
  19. Emerging Trends and AI: Emerging Tech Trends, Artificial Intelligence
  20. Paper-2 | Data Processing (Ms-Office): MS Office Applications
  21. Paper-2 | Internet and Web Technologies: HTML Basics, CSS, XML, JavaScript-Basics, Internet Fundamentals, Protocols & Services, Web Publishing & Hosting, Server Side & Security, Emerging Technologies, Terms & Abbreviations, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing
  22. Paper 2 | Pedagogy: Child Development, Theories, Concept of Pedagogy, Inclusive Education, Experiential Pedagogy, Assessment & Evaluation, Psychology, Curriculum Framework & Reforms, National Education Policy (NEP) 2020
  23. Live Classes: RSSB Live Sessions
  24. Paper 1 - Full Mock Tests:
  25. Paper 2 - Full Mock Tests:
  26. BCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video segment focuses on digital logic design, specifically demonstrating how to construct larger demultiplexers (DeMux) using smaller 1:2 DeMux units. The instructor addresses two specific problems written on the screen. First, he analyzes the requirement to implement a 1:4 DeMux. He draws a block diagram showing a hierarchical arrangement where one 1:2 DeMux feeds into two others. He derives a general formula for the number of 1:2 DeMuxes needed to build a 1:2^n DeMux, writing '2^n - 1' on the board. By substituting n=2 for the 1:4 DeMux, he calculates the result as 3. Next, he addresses the implementation of a 1:8 DeMux. He writes down powers of 2 (16, 32, 64) to establish context. He applies the formula '2^n - 1' for n=3, calculating '2^3 - 1 = 7'. He also briefly writes '2^4 - 1 = 15', likely for comparison or a 1:16 DeMux. The visual evidence includes handwritten formulas, block diagrams, and specific calculations on the whiteboard.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by addressing the first question on screen: 'Q 1 : 2 DeMux are required to implement 1 : 4 DeMux ?'. He uses a red marker to draw a block diagram illustrating the solution. The diagram shows a single 1:2 DeMux block at the input stage, which branches out to feed two subsequent 1:2 DeMux blocks. He explains the logic behind this structure. On the right side of the screen, he writes mathematical expressions to derive the answer. He writes '1:2^n' and then the formula '2^n - 1'. He calculates '2^2 - 1 = 3', circling the result to indicate that three 1:2 DeMuxes are required to build a 1:4 DeMux. He also writes 'n=2' to clarify the number of select lines.

  2. 2:00 – 2:22 02:00-02:22

    The instructor moves to the second question: 'Q 1 : 2 DeMux are required to implement 1 : 8 DeMux ?'. He writes a vertical list of numbers '16', '32', '64' on the board, likely referencing powers of 2 related to input/output lines. He then applies the previously established formula '2^n - 1' to this new problem. Since a 1:8 DeMux has 3 select lines (2^3 = 8), he writes '2^3 - 1 = 7' and circles it. He also writes '2^4 - 1 = 15' below it, possibly extending the concept to a 1:16 DeMux. The video concludes with these calculations visible on the board, reinforcing the formula for determining the number of smaller DeMux units needed.

The video provides a clear, step-by-step derivation of the formula 2^n - 1 for constructing larger DeMuxes from 1:2 units. By working through the 1:4 and 1:8 examples, the instructor demonstrates how to apply this formula to different input sizes, reinforcing the relationship between the number of select lines and the required hardware components.

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