Course Content
UPSC Notes Samples
Full Syllabus Covered | 100% as per Official UPSC Syllabus
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1. Art & Culture Sample
Covered under topic 1. Indian culture will cover the salient aspects of Art Forms, Literature and Architecture from ancient to modern times.
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1. Indian culture will cover the salient aspects of Art Forms, Literature and Architecture from ancient to modern times. (copy)
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2. Modern Indian history from about the middle of the eighteenth century until the present- significant events, personalities, issues. (copy)
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5. History of the world will include events from the 18th century such as Industrial revolution, World wars, Redrawal of national boundaries, Colonization, Decolonization, Political philosophies like Communism, Capitalism, Socialism etc.- their forms and effect on the society.
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7. Role of women and women’s organizations, Population and associated issues, Poverty and developmental issues, Urbanization, their problems and their remedies.
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10.2. Introduction to Maps
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GS2
All topics that need updates are given below.
2. Functions and responsibilities of the Union and the States, issues and challenges pertaining to the federal structure, devolution of powers and finances up to local levels and challenges therein.
All topics that need updates are given below.
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5. Parliament and State Legislatures – structure, functioning, conduct of business, powers & privileges and issues arising out of these.
All topics that need updates are given below.
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6. Structure, organization and functioning of the Executive and the Judiciary; Ministries and Departments of the Government; pressure groups and formal/informal associations and their role in the Polity.
All topics that need updates are given below.
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12. Welfare schemes for Vulnerable Sections of the Population by the Centre and States and the Performance of these schemes; Mechanisms, Laws, Institutions and Bodies constituted for the Protection and Betterment of these Vulnerable Sections.
All topics that need updates are given below.
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GS3
All topics that need updates are given below.
11. Science and Technology- developments and their applications and effects in everyday life.
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GS3: BIODIVERSITY AND ENVIRONMENT
All topics that need updates are given below.
1. Environment
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GS4
All topics that need updates are given below.
GS3: SCIENCE AND TECHNOLOGY
All topics given below
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1. Motion & Measurements
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9. Metals & Non-Metals
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10. Energy
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12. Plant Organisms
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14. Life Processes
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18. Biotechnology
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19. Information Technology
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20. Space Technology
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National & International Current Affairs (CA) 2025
Current affairs of all months are given below
delete UPSC Sample Notes [English]

i. Motion and Measurement of Time: Method, Types & Evolution

 

Dynamics of Motion through Measurement of Time

Details

In our day-to-day lives, we constantly observe objects in motion—cars traveling on roads, children playing in parks, or the simple act of walking. This motion, often governed by the interplay of forces, pressure, and friction, happens in the dimension of time and is measured over distances. The accurate measurement of time is crucial, from ancient sundials to modern quartz clocks, providing a framework for understanding the dynamics of motion in our dynamic world.

Measurement of Time: Evolution of Method of Measuring Time 

Human Necessity

Understanding and measuring time accurately is a fundamental human necessity. Ancient Way of Measurement: The measurement of time has evolved significantly from ancient methods to modern technologies. Before the invention of clocks, our ancestors had ways to measure the approximate time based on natural phenomena, like the position of the sun in the sky.

  • Nature’s Clock: The shadows cast by the sun were among the earliest tools humans used to gauge time. 
    • Sundials were made based on this principle, marking an early chapter in the measurement of time.
  • Months and Years: These were deduced from the lunar cycle and Earth’s revolution around the sun.
  • Simple Pendulum: A very basic time measuring tool, the simple pendulum consists of a metallic ball (or bob) suspended by a thread. 
    • The back-and-forth swing of this pendulum, or its oscillation, is periodic. 
    • The duration for one complete swing is called its time period.
    • Historically, this principle was used in pendulum clocks.
  • Experiment with a Pendulum: Setting up a simple pendulum and measuring its oscillations provides an understanding of periodic motion. 
    • Despite slight changes in the initial displacement, a pendulum of a specific length has a nearly constant time period. 
    • This property of the pendulum led to its use in timekeeping devices.
  • Quartz Clocks: More modern and accurate, these clocks utilize the oscillations of quartz crystals in an electric circuit to keep time.

Units of Time

  • Time: Basic unit – second (s). Other units include minutes (min) and hours (h).
  • Trivia: Galileo Galilei observed a lamp in a church oscillating back and forth and noticed that it took a constant time for each oscillation. 
    • This observation, alongside his other experiments with pendulums, paved the way for the development of pendulum clocks.
  • Comparing Time Intervals: Time can be expressed in various units based on the context. 
    • Example: While age is conveyed in years, the time to travel a short distance is usually given in minutes or hours.
  • Understanding a Second: A rough approximation of a second can be gauged by saying “two thousand and one” aloud, providing a tangible connection to the measurement of time.
  • Heart Beat: An adult’s resting heart rate also provides a perspective on time – typically beating around 72 times per minute.
  • Ancient Timekeeping: Different civilizations used various methods to measure time before pendulum clocks were invented. 
    • Sundials, water clocks, and sand clocks are examples. 
    • These devices, in their many designs, can be found across different cultures, showcasing the diverse historical approaches to the measurement of time.