| Science NCERT Exemplar Solutions (Class 6th to 10th) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6th | 7th | 8th | 9th | 10th | ||||||||||
| Science NCERT Exemplar Solutions (Class 11th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
| Science NCERT Exemplar Solutions (Class 12th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
Class 11th Physics NCERT Exemplar Solutions
1. Introduction
This introductory chapter sets the stage for studying physics, exploring the scope and excitement of the subject. It discusses physics's relationship with technology and society, highlighting how scientific discoveries lead to technological advancements and vice-versa, a driving force for progress in India and globally. It introduces the fundamental forces of nature (gravitational, electromagnetic, strong, weak nuclear forces) and touches upon the core ideas of unification and reduction, illustrating how physics seeks to explain diverse phenomena through simple, universal laws.
2. Units And Measurements
Accurate measurement is the cornerstone of physics. This chapter introduces **physical quantities**, fundamental and derived units, and the globally accepted **International System of Units (SI Units)**. It covers the measurement of length, mass, and time, including large and small distances and masses. **Dimensional analysis** is introduced as a powerful tool for checking the consistency of equations and deriving relationships between physical quantities. Errors in measurement (systematic and random) and the concept of **significant figures** are discussed, emphasizing the precision and reliability essential for scientific experimentation and data analysis.
3. Motion In A Straight Line
This chapter describes **motion** along a straight path, the simplest type of movement. It introduces key kinematic concepts like position, path length (distance), displacement (a vector quantity), speed, velocity (a vector quantity), and acceleration (the rate of change of velocity). Different types of motion, including uniform and non-uniform motion, are discussed. The chapter uses **graphs** (position-time, velocity-time, acceleration-time) to represent motion. The fundamental **equations of motion** for uniformly accelerated motion ($\textsf{v = u + at}$, $\textsf{s = ut} + \frac{1}{2}\textsf{at}^2$, $\textsf{v}^2 - \textsf{u}^2 = 2\textsf{as}$) are derived and applied to solve problems, providing a quantitative framework for linear motion.
4. Motion In A Plane
Extending the study of motion to two dimensions, this chapter deals with **motion in a plane**. It introduces **vectors** as quantities possessing both magnitude and direction, crucial for describing motion in multiple dimensions. Vector algebra, including addition, subtraction, and resolution of vectors into components, is explained. Key topics include **projectile motion**, where an object moves under gravity along a parabolic path (analyzed using vector components), and **uniform circular motion**, involving constant speed but continuously changing velocity direction due to **centripetal acceleration** ($\textsf{a}_\text{c} = \frac{\textsf{v}^2}{\textsf{r}}$). Understanding vectors is essential for analyzing complex movements.
5. Laws Of Motion
This chapter presents the fundamental relationship between **force** and **motion** through **Newton's Laws of Motion**. Newton's First Law describes **inertia** – the inherent property of an object to resist changes in its state of rest or uniform motion. The Second Law quantifies force, stating that net force equals the rate of change of momentum ($\vec{\textsf{F}} = \frac{\textsf{d}\vec{\textsf{p}}}{\textsf{dt}} = \textsf{m}\vec{\textsf{a}}$ for constant mass). The Third Law states that for every action, there is an equal and opposite reaction. Concepts like **momentum** ($\vec{\textsf{p}} = \textsf{m}\vec{\textsf{v}}$), impulse, and the principle of **conservation of linear momentum** are derived and applied to understand various interactions, including collisions.
6. Work, Energy And Power
This chapter introduces the fundamental concepts of **work**, **energy**, and **power**, central to mechanics and thermodynamics. **Work** is done by a force when it causes displacement ($\textsf{W} = \vec{\textsf{F}} \cdot \vec{\textsf{s}}$). **Energy** is defined as the capacity to do work, discussed in various forms, focusing on mechanical energy (kinetic and potential). **Kinetic energy** ($\textsf{KE} = \frac{1}{2}\textsf{mv}^2$) is energy of motion. Potential energy is stored energy (e.g., gravitational $\textsf{PE} = \textsf{mgh}$, elastic). The **Work-Energy Theorem** and the **Law of Conservation of Energy** are pivotal. **Power** is defined as the rate of doing work ($\textsf{P} = \frac{\textsf{W}}{\textsf{t}}$).
7. System Of Particles And Rotational Motion
This chapter extends the analysis of motion from single particles to **systems of particles** and **rigid bodies**, introducing **rotational motion**. Concepts like the **center of mass** (the point representing the average position of all parts of the system, where external forces act) are introduced. **Torque** ($\vec{\tau} = \vec{\textsf{r}} \times \vec{\textsf{F}}$) is defined as the rotational equivalent of force, causing angular acceleration. **Angular momentum** ($\vec{\textsf{L}} = \textsf{I}\vec{\omega}$) is the rotational equivalent of linear momentum. **Moment of inertia** ($\textsf{I}$) quantifies resistance to rotational acceleration. The relationship between linear and angular variables and the **conservation of angular momentum** are key principles.
8. Gravitation
This chapter explores the fundamental attractive force between any two objects with mass: **gravitation**. **Newton's Law of Universal Gravitation** ($\textsf{F} = \textsf{G}\frac{\textsf{m}_1\textsf{m}_2}{\textsf{r}^2}$) is the cornerstone. Concepts like free fall and **acceleration due to gravity** ($\textsf{g}$), its variation with altitude and depth, and gravitational potential energy are discussed. **Escape speed** (minimum speed to escape a gravitational field) and **orbital velocity** of satellites are derived. **Kepler's laws** describing planetary motion are presented, explained through universal gravitation. This chapter provides a foundation for understanding planetary orbits, satellite motion, and the structure of the universe.
9. Mechanical Properties Of Solids
This chapter investigates the behaviour of **solid materials** when subjected to deforming forces, focusing on their **elastic properties**. Concepts like **stress** (force per unit area) and **strain** (relative deformation) are introduced. **Hooke's Law**, which states that stress is directly proportional to strain within the elastic limit ($\textsf{Stress} = \textsf{E} \times \textsf{Strain}$), is central. Different moduli of elasticity – **Young's modulus** (for stretching/compression), **Shear modulus** (for twisting/shearing), and **Bulk modulus** (for volume change under pressure) – are defined. The **stress-strain curve** is discussed, illustrating elastic and plastic behaviour, providing insights into material strength and stiffness, relevant in engineering and structural design.
10. Mechanical Properties Of Fluids
This chapter explores the behaviour of **fluids** (liquids and gases) both at rest (**fluid statics**) and in motion (**fluid dynamics**). Fluid statics covers concepts like **pressure** (force per unit area), **Pascal's Law** (pressure transmission), and **Archimedes' principle** (**buoyancy**). Fluid dynamics introduces **viscosity** (resistance to flow) and **surface tension** (tendency of liquids to minimize surface area). Different types of fluid flow (streamline and turbulent) are discussed. **Bernoulli's principle** ($\textsf{P} + \frac{1}{2}\rho\textsf{v}^2 + \rho\textsf{gh} = \textsf{constant}$), based on energy conservation for ideal fluid flow, is a key concept with numerous applications, e.g., in aeroplanes and fluid pipelines.
11. Thermal Properties Of Matter
This chapter focuses on how **heat** and **temperature** affect materials. It discusses the relationship between heat and thermal energy transfer. **Temperature scales** (Celsius, Fahrenheit, Kelvin) and their conversions are explained. **Thermal expansion** – the tendency of matter to change volume in response to temperature changes – in solids, liquids, and gases is covered. Concepts like **specific heat capacity** and **latent heat** are introduced, quantifying the energy involved in temperature changes and **phase transitions** (melting, boiling). The three primary modes of **heat transfer** – conduction, convection, and radiation – are detailed, explaining how heat energy moves.
12. Thermodynamics
**Thermodynamics** is the branch of physics dealing with heat and its conversion into other forms of energy and work. This chapter introduces fundamental concepts like thermodynamic systems, surroundings, state variables, and **internal energy**. The **First Law of Thermodynamics** ($\Delta \textsf{U} = \textsf{Q} + \textsf{W}$), essentially the conservation of energy for thermodynamic systems, and various **thermodynamic processes** (isothermal, adiabatic, isobaric, isochoric) are discussed. The **Second Law of Thermodynamics** introduces the concept of **entropy** ($\Delta \textsf{S}$) and dictates the spontaneity and direction of natural processes, explaining the limitations on the efficiency of converting heat into work, as seen in **heat engines** and refrigerators.
13. Kinetic Theory
This chapter explains the macroscopic properties of gases from a microscopic viewpoint using the **Kinetic Theory of Gases**. It models gases as composed of a large number of particles (molecules) in constant, random motion. The postulates of the theory are discussed. It explains how concepts like **pressure** arise from molecular collisions with container walls and how **temperature** is directly proportional to the average kinetic energy of the molecules. The **Ideal Gas Equation** ($\textsf{PV = nRT}$) is derived from kinetic theory. Concepts like degrees of freedom and the **Law of Equipartition of Energy** are introduced, providing insights into the internal energy and specific heat capacities of gases.
14. Oscillations
This chapter explores **oscillations**, periodic motions that repeat over time, like the swing of a pendulum or a mass vibrating on a spring. It focuses specifically on **Simple Harmonic Motion (SHM)**, the most fundamental type, where the restoring force is directly proportional to the displacement from equilibrium and acts towards the equilibrium position. Concepts like displacement, velocity, acceleration, amplitude, time period (T), frequency ($\nu$), angular frequency ($\omega = \sqrt{\textsf{k/m}}$), and phase are discussed. The energy in SHM (sum of kinetic and potential energy) is shown to be constant. Examples like the **simple pendulum** and a mass attached to a spring are analyzed.
15. Waves
This chapter introduces **wave motion** as the phenomenon where a disturbance propagates through a medium or vacuum, transferring energy and momentum without bulk movement of matter. It distinguishes between **transverse waves** (particles vibrate perpendicular to propagation, e.g., light, waves on a string) and **longitudinal waves** (particles vibrate parallel to propagation, e.g., sound). Key wave properties – amplitude, wavelength ($\lambda$), frequency ($\nu$), time period (T), and **wave speed** ($\textsf{v} = \nu\lambda$) – are defined. The **principle of superposition** is introduced, explaining phenomena like **interference** and the formation of **standing waves**. Reflection of waves is also covered.
Sample Paper I
This entry provides **Sample Paper I**, a practice test specifically designed for students using the Class 11th Physics NCERT Exemplar Solutions. It contains a comprehensive set of questions covering the concepts and problem-solving techniques discussed in Chapters 1 through 15. Attempting this sample paper under timed conditions is invaluable for self-assessment, identifying areas of strength and weakness, improving speed and accuracy, and gaining confidence before examinations. It simulates the exam environment, helping students prepare effectively.
Sample Paper II
This entry presents **Sample Paper II**, offering a second opportunity for students to practice and reinforce their understanding of the Class 11th Physics syllabus covered in the NCERT Exemplar Solutions. This paper provides another set of varied questions from all chapters, allowing students to encounter different question formats and difficulty levels. Solving both sample papers helps in thorough revision, strengthening conceptual clarity, and improving problem-solving efficiency, which is crucial for scoring well in physics examinations.