Important Practice Questions

Duration: 36 min

This video lesson is available to enrolled students.

Return to /learn/BIHAR-STET-COMPUTER-SCIENCE-COMPLETE-COURSE/logical-reasoning/clock/basic-concepts-and-clock-mechanics/asset-important-practice-questions after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About the course: About the Course
  2. Mathematical Aptitude: संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Divisibility Rules, प्रतिशत / Percentage, अनुपात और समानुपात / Ratio and Proportion, औसत / Average, लाभ, हानि और बट्टा / Profit, Loss and Discount, समय और कार्य / Time and Work, घन क्षेत्रमिति / Solid Mensuration, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, समय, चाल और दूरी / Time, Speed and Distance, Age Problems, मिश्रण और एलिगेशन / Mixture and Alligation, Algebra, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, Pipe and Cistern, Trigonometry, Statistics, आँकड़ा निर्वचन / Data Interpretation, Arithmetic, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers
  3. Logical Reasoning: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, सादृश्यता एवं वर्गीकरण / Analogy and Classification, रक्त संबंध / Blood Relations, दिशा एवं दूरी / Direction and Distance, क्रम एवं रैंकिंग / Order and Ranking, अशाब्दिक तर्क / Non-Verbal Reasoning, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, Syllogisms, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, Analytical Reasoning (Counting Figures Reasoning), घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, कैलेंडर एवं घड़ी / Calendar and Clock, Clock
  4. General Knowledge: वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Chemistry, Biology, History, Geography, Polity, Indian Economy, समसामयिकी / Current Affairs, Static General Knowledge, राज्य विशेष सामान्य ज्ञान / State-Specific General Knowledge
  5. Art of Teaching: शिक्षण-अधिगम प्रक्रिया एवं कक्षा प्रबंधन / Teaching-Learning Process and Classroom Management, Learners & Learning Process, Factors Affecting Teaching, शिक्षण विधियाँ एवं उपागम / Teaching Methods and Approaches, सूक्ष्म शिक्षण एवं कक्षा संप्रेषण / Microteaching and Classroom Communication, शिक्षण सहायक सामग्री एवं शैक्षिक तकनीकी / Teaching Aids and Educational Technology, आकलन एवं मूल्यांकन / Assessment and Evaluation, शिक्षक: गुण, व्यावसायिक नैतिकता एवं विकास / Teacher: Qualities, Professional Ethics and Development, शैक्षिक नीतियाँ, अधिनियम एवं प्रशासन / Educational Policies, Acts and Administration, पाठ्यचर्या, कला एवं सह-शैक्षिक क्षेत्र / Curriculum, Arts and Co-curricular Areas, निर्देशन एवं परामर्श / Guidance and Counselling, दिव्यांग बच्चों की शिक्षा / Education of Children with Disabilities, Micro-Teaching & Teaching Skills, पाठ योजना / Lesson Planning
  6. Environmental Science: Environment
  7. Unit 1 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  8. Unit 2 | COA: 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
  9. Unit 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  10. Unit 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  11. Unit 4 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  12. Unit 5 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management
  13. Unit 6 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Transaction Management, Concurrency Control
  14. Unit 7 | Computer Networks: 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
  15. Unit 8 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  16. Unit 9 | Object Oriented Programming: OOPS with C++
  17. Unit 10 | Web Development: HTML Basics, CSS, JavaScript-Basics, XML, Node.js, Git & Github, PHP
  18. Unit 11 | 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
  19. Unit 12 | IoT: Emerging Tech Trends, Cloud Computing, कंप्यूटर नेटवर्क / Computer Networks
  20. Unit 13 | Artificial Intelligence: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms
  21. Unit 14 | E-Commerce: Electronic Data Interchange and E-Commerce, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Physical Security and Cryptography Basics, Cyber Safety and Security
  22. Unit 15 | Multimedia: Multimedia
  23. Unit 16 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  24. Full Length Mock Tests — General Paper:
  25. Full Length Mock Tests — Computer Science (Paper II):
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This video is a comprehensive lecture on clock problems, a common topic in competitive exams. The instructor, Yash Jain Sir, systematically explains and solves various types of questions. The lesson begins with a problem calculating the total distance covered by the hour and minute hands of a clock over 4 days, using the formula for the circumference of a circle (2πr). He then moves to finding the angle between the hands at specific times, such as 8:40, using the formula 30H - 11/2M. The lecture continues with a question on how many times the hands coincide in 5 hours, which is solved by first determining the time interval between coincidences (65 5/11 minutes) and then calculating how many such intervals fit into 5 hours. The final problem asks for the exact time between 6 and 7 when the hands coincide, which is solved by setting up the equation 30H = 11/2M. The video uses a digital blackboard for clear, step-by-step demonstrations, making it a valuable resource for students preparing for exams like TCS and other aptitude tests.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card featuring the word "CLOCKS" over an image of multiple clocks hanging from chains. It then transitions to a lecture where the instructor, Yash Jain Sir, introduces the first problem. The question displayed on the screen asks for the total distance covered by the long hand (8cm) and short hand (7cm) of a clock in 4 days. The instructor begins to explain the concept, noting that the hands move in a circular path, and the distance covered is the circumference of the circle they trace.

  2. 2:00 – 5:00 02:00-05:00

    The instructor explains that the long hand (minute hand) completes 24 rounds in a day, and the short hand (hour hand) completes 2 rounds in a day. He draws a diagram of a clock with the long hand labeled 8cm. He then writes the formula for the circumference of a circle, 2πr, and begins to calculate the distance covered by the long hand in one day as 24 * 2π * 8. He also calculates the distance for the short hand as 2 * 2π * 7. He then multiplies these daily distances by 4 to get the total distance for 4 days.

  3. 5:00 – 10:00 05:00-10:00

    The instructor continues the calculation, writing the full expression for the total distance: 4 * (24 * 2π * 8 + 2 * 2π * 7). He simplifies this to 4 * 2π * (24 * 8 + 2 * 7), which becomes 4 * 2π * (192 + 14) = 4 * 2π * 206. He then calculates 4 * 2 * 206 = 1648, resulting in a total distance of 1648π cm. He confirms this is the correct answer, which is option C. He then moves to the next problem, which asks for the angle between the hands at 8:40.

  4. 10:00 – 15:00 10:00-15:00

    The instructor explains the formula for the angle between the hands: 30H - 11/2M, where H is the hour and M is the minute. He applies this to the time 8:40, writing 30 * 8 - 11/2 * 40. He calculates 240 - 220 = 20 degrees. He then moves to the next problem, which asks for the angle at 6:20. He applies the same formula: 30 * 6 - 11/2 * 20 = 180 - 110 = 70 degrees. He then moves to the next problem, which asks for the angle at 10:10.

  5. 15:00 – 20:00 15:00-20:00

    The instructor applies the formula to 10:10: 30 * 10 - 11/2 * 10 = 300 - 55 = 245 degrees. He notes that the angle is 245 degrees, but the smaller angle is 360 - 245 = 115 degrees. He then moves to the next problem, which asks for the angle at 1:10. He applies the formula: 30 * 1 - 11/2 * 10 = 30 - 55 = -25 degrees. He explains that the negative sign indicates the direction, and the angle is 25 degrees. He then moves to the next problem, which asks for the angle between the hands at 5:30.

  6. 20:00 – 25:00 20:00-25:00

    The instructor explains that the hour hand moves as the minutes pass. He calculates the angle of the hour hand at 5:30 as 5 * 30 + 30 * 0.5 = 150 + 15 = 165 degrees. He calculates the angle of the minute hand as 30 * 6 = 180 degrees. The difference is 180 - 165 = 15 degrees. He confirms this is the correct answer, which is option C. He then moves to the next problem, which asks how many times the hands coincide in 5 hours.

  7. 25:00 – 30:00 25:00-30:00

    The instructor explains that the hands coincide 11 times in 12 hours. He calculates the time interval between coincidences as 12 hours / 11 = 720 minutes / 11 = 65 5/11 minutes. He then calculates how many such intervals fit into 5 hours (300 minutes). He writes the equation: n = 300 / (65 5/11) = 300 / (720/11) = 300 * 11 / 720 = 3300 / 720 = 4.583. He concludes that the hands coincide 4 times in 5 hours, which is option A. He then moves to the next problem, which asks for the time between 6 and 7 when the hands coincide.

  8. 30:00 – 35:00 30:00-35:00

    The instructor explains that the hands coincide when the minute hand catches up to the hour hand. He sets up the equation 30H = 11/2M, where H is the hour and M is the minute. For the time between 6 and 7, H = 6. He substitutes this into the equation: 30 * 6 = 11/2 * M, which gives 180 = 11/2 * M. He solves for M: M = 180 * 2 / 11 = 360 / 11 = 32 8/11 minutes. He concludes that the hands coincide at 6:32 8/11, which is option C. He then moves to the final problem, which asks for the number of times the hands coincide between 9 a.m. and 9 p.m.

  9. 35:00 – 36:21 35:00-36:21

    The instructor explains that between 9 a.m. and 9 p.m. is a 12-hour period. He states that the hands coincide 11 times in every 12 hours. He confirms that the answer is 11, which is option C. The video ends with a "THANKS FOR WATCHING" screen.

The video provides a structured and methodical approach to solving clock problems, a common topic in quantitative aptitude. It begins with a fundamental problem involving the calculation of distance covered by the clock hands, which requires understanding the circular motion and the formula for circumference. The instructor then transitions to the more common problem of finding the angle between the hands, introducing the formula 30H - 11/2M and demonstrating its application to various times. The lesson progresses to more complex problems, such as determining the number of times the hands coincide in a given period, which requires understanding the relative speeds of the hands and the time interval between coincidences. The final problem involves solving for the exact time of coincidence, which is a direct application of the formula. The consistent use of a digital blackboard and clear, step-by-step explanations makes the concepts accessible and easy to follow, providing a comprehensive review for students preparing for competitive exams.

Loading lesson…