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NCERT SOLUTIONS

CLASS 9 MATHEMATICS

NCERT SOLUTIONS

  1. Number System

    2.

  2. Polynomials

  3. Coordinate Geometry

    4.

  4. Linear Equations in Two Variables

    5.

  5. Introduction to Euclid’s Geometry

    6.

  6. Lines and Angles

    7.

  7. Triangles

  8. Quadrilaterals

  9. Areas of Parallelograms and Triangles

    10.

  10. Circles

    11.

  11. Constructions

    12.

  12. Heron’s Formula

    13.

  13. Surface Areas and Volumes

    14.

  14. Statistics

    15.

  15. Probability

    16.

CLASS 9 SCIENCE

NCERT SOLUTIONS

  1. Matter In Our Surroundings

  2. Is Matter Around Us Pure

  3. Atoms And Molecules

  4. Structure Of The Atom

    5.

  5. The Fundamental Unit Of Life

  6. Tissues

    7.

  7. Diversity In Living Organisms

    8.

  8. Motion

  9. Force And Laws Of Motion

    10.

  10. Gravitation

    11.

  11. Work And Energy

    12.

  12. Sound

    13.

  13. Why Do We Fall Ill

    14.

  14. Natural Resources

    15.

  15. Improvement In Food Resources

    16.

CLASS 10 MATHEMATICS

NCERT SOLUTIONS

  1. Real Numbers

    2.

  2. Polynomials

  3. Pair of Linear Equations in Two Variables

    4.

  4. Quadratic Equations

    5.

  5. Arithmetic Progressions

    6.

  6. Triangles

    7.

  7. Coordinate Geometry

  8. Introduction to Trigonometry

    9.

  9. Some Applications of Trigonometry

    10.

  10. Circles

    11.

  11. Constructions

    12.

  12. Areas Related to Circles

    13.

  13. Surface Areas and Volumes

    14.

  14. Statistics

    15.

  15. Probability

    16.

CLASS 10 SCIENCE

NCERT SOLUTIONS
  1. Chemical Reactions and Equations

    2.
  2. Acids, Bases and Salts

    3.
  3. Metals and Non-metals

    4.
  4. Carbon and its Compounds

    5.
  5. Periodic Classification of Elements

    6.
  6. Life Processes

    7.
  7. Control and Coordination

    8.
  8. How do Organisms Reproduce?

    9.
  9. Heredity and Evolution

    10.
  10. Light – Reflection and Refraction

    11.
  11. Human Eye and Colourful World

    12.
  12. Electricity

    13.
  13. Magnetic Effects of Electric Current

    14.
  14. Sources of Energy

    15.
  15. Our Environment

    16.
  16. Management of Natural Resources

    17.

CLASS 11 MATHEMATICS

NCERT SOLUTIONS

  1. Sets

    2.

  2. Relations and Functions

    3.

  3. Trigonometric Functions

  4. Principle of Mathematical Induction

  5. Complex Numbers and Quadratic Equations

  6. Linear Inequalities

  7. Permutations and Combinations

  8. Binomial Theorem

  9. Sequences and Series

  10. Straight Lines

  11. Conic Sections

  12. Introduction to Three Dimensional Geometry

  13. Limits and Derivatives

  14. Mathematical Reasoning

  15. Statistics

  16. Probability

CLASS 11 PHYSICS

NCERT SOLUTIONS

Chapter 2. Units and Measurements

Chapter 3. Motion in a Straight Line

Chapter 4. Motion in a Plane

Chapter 5. Laws of Motion

Chapter 6. Work, Energy and Power

Chapter 7. System of Particles and Rotational Motion

Chapter 8. Gravitation

Chapter 9. Mechanical Properties Of Solids

Chapter 10. Mechanical Properties Of Fluids

Chapter 11. Thermal Properties Of Matter

Chapter 12. Thermodynamics

Chapter 13. Kinetic Theory

Chapter 14. Oscillations

Chapter 15. Waves

CLASS 11 CHEMISTRY

NCERT SOLUTIONS

  1. Some Basic Concepts of Chemistry

    2.

  2. Structure of Atom

    3.

  3. Classification of Elements and Periodicity in Properties

  4. Chemical Bonding and Molecular Structure

  5. States of Matter

  6. Thermodynamics

  7. Equilibrium

  8. Redox Reactions

  9. Hydrogen

  10. The s-Block Elements

  11. The p-Block Elements

  12. Organic Chemistry – Some Basic Principles and Techniques

  13. Hydrocarbons

  14. Environmental Chemistry

CLASS 11 ECONOMICS

NCERT SOLUTIONS

PART I - INDIAN ECONOMY

  1. Indian Economy on the Eve of Independence

    2.

  2. Indian Economy:1950-1990

    3.

  3. IE-3. Economic Reforms Since 1991

  4. IE-4. Poverty

  5. IE-5. Human Capital Formation in India

  6. IE-6. Rural Development

  7. IE-7. Employment : Growth, Information and Other Issues

  8. IE-8. Infrastructure

  9. IE-9. Environment and Sustainable Development

  10. IE-10. Development Experiences of India : A Comparison with Neighbours

PART II - STATISTICS IN ECONOMICS

  1. Introduction to Economics

    2.

  2. Stat-2. Collection of Data

  3. Stat-3. Organization of Data

  4. Stat-4. Presentation of Data

  5. Stat-5. Measures of Central Tendency

  6. Stat-6. Measures of Dispersion

  7. Stat-7. Correlation

  8. Stat-8. Index Numbers

  9. Stat-9. Use of Statistical Tools

CLASS 12 MATHEMATICS

NCERT SOLUTIONS

  1. Relations and Functions

    2.

  2. Inverse Trigonometric Functions

  3. Matrices

  4. Determinants

  5. Continuity and Differentiability

  6. Application of Derivatives

  7. Integrals

  8. Application of Integrals

  9. Differential Equations

  10. Vector Algebra

  11. Three Dimensional Geometry

  12. Linear Programming

  13. Limits and Derivatives

  14. Probability

  15. Supplementary Material

CLASS 12 PHYSICS

NCERT SOLUTIONS

  1. Electric Charges And Fields

    2.

  2. Electrostatic Potential And Capacitance

  3. Current Electricity

    4.

  4. Moving Charges And Magnetism

  5. Magnetism And Matter

    6.

  6. Electromagnetic Induction

    7.

  7. Electromagnetic Waves

  8. Ray Optics And Optical Instruments

  9. Wave Optics

  10. Dual Nature Of Radiation And Matter

  11. Atoms

  12. Nuclei

  13. Semiconductor Electronics: Materials, Devices And Simple Circuits

  14. Communication Systems

CLASS 12 CHEMISTRY

NCERT SOLUTIONS

  1. The Solid State

    2.

  2. Solutions

    3.

  3. Electrochemistry

    4.

  4. Chemical Kinetics

    5.

  5. Surface Chemistry

  6. General Principles and Processes of Isolation of Elements

  7. The p-Block Elements

  8. The d-and f-Block Elements

  9. Coordination Compounds

  1. Haloalkanes and Haloarenes

    2.

  2. Alcohols, Phenols and Ethers

  3. Aldehydes, Ketones and Carboxylic Acids

  4. Amines

  5. Biomolecules

  6. Polymers

  7. Chemistry in Everyday Life

CLASS 12 ECONOMICS

NCERT SOLUTIONS

READERS' QUESTIONS

Q: A spaceship is stationed on Mars. How much energy must be expended on the spaceship to launch it out of the solar system? Mass of the space ship = 1000 kg; mass of the Sun = 2 × 1030 kg; mass of mars = 6.4 × 1023 kg; radius of mars = 3395 km; radius of the orbit of mars = 2.28 × 108 kg; G= 6.67 × 10–11 N m2 kg–2.

More questions like this

Answer:

Given,

Mass of the spaceship, m = 1000 kg

Mass of the Sun, MS = 2 × 1030 kg

Mass of Mars, MM = 6.4 × 1023 kg

Orbital radius of Mars, R = 2.28 × 108 km =2.28 × 1011 m

Radius of Mars, r = 3395 km = 3.395 × 106 m

Universal gravitational constant, G= 6.67 × 10–11 N m2 kg–2

Potential energy of the spaceship due to the gravitational attraction of the Sun

VS=- GMS mR

Potential energy of the spaceship due to the gravitational attraction of Mars

VM=- GMM mr

Since, the spaceship is stationed on Mars, its velocity and hence, its kinetic energy will be zero.

Therefore, total energy of the spaceship

V=VS+VM==- GMS mR- GMM mr=- GmMSR+MMr

The negative sign indicates that the system is in bound state.

Energy required for launching the spaceship out of the solar system

= – (Total energy of the spaceship)

= GmMSR+MMr

=6.67 ×10–11×1000×2 × 10302.28 × 1011 +6.4 × 10233.395 × 106

=6.67 ×10–8×87.72 × 1017+1.88 × 1017

=6.67 ×10–8×89.50 × 1017

=598× 109 J

 6× 1011 J

Q: An oil drop of 12 excess electrons is held stationary under a constant electric field of 2.55 × 104 N C−1 in Millikan’s oil drop experiment. The density of the oil is 1.26 g cm−3. Estimate the radius of the drop. (g = 9.81 m s−2; e = 1.60 × 10−19 C).

More questions like this

Answer:

Since the drop is stationary, force (FE) due to electric field E is equal to the weight of the oil drop (W)

Let the radius of the oil drop be r

Mass of the oil drop m = Volume of the drop × Density of oil

m =43πr3×ρ 

W=mg=43πr3×ρ×g  

Electrostatic Force FE = qE

Excess electrons on an oil drop, n = 12

Charge on an electron, e = 1.6 × 10−19 C

q = Net charge on the oil drop = n e

= 12 × 1.6 × 10−19 C

Electric field intensity, E = 2.55 × 104 N C−1

Density of oil, ρ = 1.26 gm/cm3 = 1.26×103 kg/m3

Acceleration due to gravity, g = 9.81 m s−2

Putting the values in

E n e=43πr3×ρ×g 

r=3Ene4πρg3

=3×2.55×104×12×1.6×10-194×3.14×1.26×103×9.813

=946.09×10-213=9.82×10-7 m