Shape and Size of Earth
Duration: 3 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- About the course: About the Course
- Mathematical Aptitude / गणितीय अभिक्षमता: Number System / संख्या पद्धति, HCF and LCM / महत्तम समापवर्तक और लघुत्तम समापवर्त्य, Divisibility Rules / विभाज्यता के नियम, Percentage / प्रतिशत, Ratio and Proportion / अनुपात और समानुपात, Average / औसत, Profit, Loss and Discount / लाभ, हानि और बट्टा, Time and Work / समय और कार्य, Solid Mensuration / घन क्षेत्रमिति, Simple and Compound Interest / साधारण और चक्रवृद्धि ब्याज, Time, Speed and Distance / समय, चाल और दूरी, Age Problems / आयु संबंधी प्रश्न, Mixture and Alligation / मिश्रण और एलिगेशन, Algebra / बीजगणित, Simplification, Indices and Surds / सरलीकरण, घातांक और करणी, Pipe and Cistern / नल और टंकी, Trigonometry / त्रिकोणमिति, Statistics / सांख्यिकी, Data Interpretation / आँकड़ा निर्वचन, Arithmetic / अंकगणित, Sets, Relations, Functions and Discrete Mathematics / समुच्चय, संबंध, फलन और विविक्त गणित, Number Systems and Number Theory / संख्या पद्धति और संख्या सिद्धांत, Coordinate Geometry, Vectors and 3D Geometry / निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति, Polynomials, Equations and Complex Numbers / बहुपद, समीकरण और सम्मिश्र संख्याएँ
- Logical Reasoning / तार्किक तर्कशक्ति: Series / श्रेणी, Coding-Decoding / कूट लेखन एवं कूट वाचन, Analogy and Classification / सादृश्यता एवं वर्गीकरण, Blood Relations / रक्त संबंध, Direction and Distance / दिशा एवं दूरी, Order and Ranking / क्रम एवं रैंकिंग, Non-Verbal Reasoning / अशाब्दिक तर्क, Seating Arrangement and Puzzles / बैठक व्यवस्था एवं पहेलियाँ, Syllogisms / न्यायवाक्य, Venn Diagrams, Syllogism and Inequalities / वेन आरेख, न्याय वाक्य एवं असमानता, Mathematical Operations and Missing Numbers / गणितीय संक्रियाएँ एवं लुप्त संख्या, Alphabet and Number Test / वर्णमाला एवं संख्या परीक्षण, Statement-Based Reasoning / कथन आधारित तार्किक विवेचन, Analytical Reasoning (Counting Figures Reasoning) / विश्लेषणात्मक तर्क (आकृति गणना तर्क), Cubes, Dice and Figure Counting / घन, पासा एवं आकृतियों की गिनती, Calendar and Clock / कैलेंडर एवं घड़ी, Clock / घड़ी
- General Knowledge / सामान्य ज्ञान: Scientific Achievements and Research / वैज्ञानिक उपलब्धियाँ और अनुसंधान, Chemistry / रसायन विज्ञान, Biology / जीव विज्ञान, History / इतिहास, Geography / भूगोल, Polity / राजव्यवस्था, Indian Economy / भारतीय अर्थव्यवस्था, Current Affairs / समसामयिकी, Static General Knowledge / स्थैतिक सामान्य ज्ञान, State-Specific General Knowledge / राज्य विशेष सामान्य ज्ञान
- Art of Teaching / शिक्षण कला: Teaching-Learning Process and Classroom Management / शिक्षण-अधिगम प्रक्रिया एवं कक्षा प्रबंधन, Learners & Learning Process / अधिगमकर्ता और अधिगम प्रक्रिया, Factors Affecting Teaching / शिक्षण को प्रभावित करने वाले कारक, Teaching Methods and Approaches / शिक्षण विधियाँ एवं उपागम, Microteaching and Classroom Communication / सूक्ष्म शिक्षण एवं कक्षा संप्रेषण, Teaching Aids and Educational Technology / शिक्षण सहायक सामग्री एवं शैक्षिक तकनीकी, Assessment and Evaluation / आकलन एवं मूल्यांकन, Teacher: Qualities, Professional Ethics and Development / शिक्षक: गुण, व्यावसायिक नैतिकता एवं विकास, Educational Policies, Acts and Administration / शैक्षिक नीतियाँ, अधिनियम एवं प्रशासन, Curriculum, Arts and Co-curricular Areas / पाठ्यचर्या, कला एवं सह-शैक्षिक क्षेत्र, Guidance and Counselling / निर्देशन एवं परामर्श, Education of Children with Disabilities / दिव्यांग बच्चों की शिक्षा, Micro-Teaching & Teaching Skills / सूक्ष्म शिक्षण और शिक्षण कौशल, Lesson Planning / पाठ योजना
- Environmental Science / पर्यावरण विज्ञान: Environment / पर्यावरण
- Unit 1 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
- 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
- Unit 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
- Unit 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
- Unit 4 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
- 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
- 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
- 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
- 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
- Unit 9 | Object Oriented Programming: OOPS with C++
- Unit 10 | Web Development: HTML Basics, CSS, JavaScript-Basics, XML, Node.js, Git & Github, PHP
- 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
- Unit 12 | IoT: Emerging Tech Trends, Cloud Computing, Computer Networks, Internet of Things
- Unit 13 | Artificial Intelligence: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms
- 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
- Unit 15 | Multimedia: Multimedia
- 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
- Full Length Mock Tests — General Paper:
- Full Length Mock Tests — Computer Science (Paper II):
- Full Length Mock Test – General + Computer Science:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
The video is a physics lecture explaining the concept of geostationary orbits. The instructor uses a digital drawing interface over an image of Earth to illustrate key principles. The lesson begins by defining a geostationary satellite as one that remains fixed over a point on the equator, which requires it to orbit with the same period as Earth's rotation (24 hours). The instructor then explains that for a satellite to be geostationary, its orbital plane must be the same as Earth's equatorial plane. The core of the lecture focuses on calculating the orbital radius of such a satellite using the formula for centripetal force provided by gravity, GMm/r^2 = mω^2r. The video demonstrates the step-by-step derivation of the formula for the orbital radius, r = (GMT^2/4π^2)^(1/3), and then applies it to find the height of the satellite above the Earth's surface. The final calculation shows the satellite is approximately 36,000 km above the surface, which is a standard value for geostationary orbits.
Chapters
0:00 – 2:00 00:00-02:00
The video opens with a view of Earth from space, with the instructor in a small window. The instructor begins by defining a geostationary satellite as one that appears stationary from the ground, which requires it to orbit the Earth with a period of 24 hours. The instructor explains that for this to happen, the satellite's orbit must be in the equatorial plane. A yellow line is drawn vertically through the center of the Earth, representing the axis of rotation. The instructor then introduces the concept of centripetal force, which is provided by gravity, and writes the equation for the force of gravity (GMm/r^2) and the centripetal force (mω^2r). The instructor states that for a stable orbit, these two forces must be equal, leading to the equation GMm/r^2 = mω^2r. The instructor then begins to solve this equation for the orbital radius, r.
2:00 – 3:28 02:00-03:28
The instructor continues the derivation, canceling the mass of the satellite (m) from both sides of the equation, resulting in GM/r^2 = ω^2r. The equation is then rearranged to solve for r^3, yielding r^3 = GM/ω^2. The instructor then substitutes the angular velocity (ω) with 2π/T, where T is the period of 24 hours, leading to the final formula r^3 = GMT^2/4π^2. The instructor then calculates the value of r, which is the distance from the center of the Earth to the satellite. The video shows the calculation of the orbital radius, which is approximately 42,000 km. The instructor then subtracts the Earth's radius (6,400 km) to find the height of the satellite above the surface, which is approximately 36,000 km. The instructor concludes by stating that this is the standard height for a geostationary satellite.
The video provides a clear, step-by-step derivation of the orbital radius for a geostationary satellite. It begins with the fundamental requirement of a 24-hour orbital period and an equatorial orbit, then uses the principle of force balance (gravity providing centripetal force) to derive the necessary formula. The lecture effectively combines conceptual explanation with mathematical derivation, culminating in a practical calculation that confirms the standard height of 36,000 km for such satellites, making the complex physics accessible through a logical and visual approach.

