NCERT Solutions for Class 11 Physics Chapter 1

Physics is considered to be one of the toughest subjects for students as it has many concepts and theories. The subject is important not only from the board exams’ perspective, but also holds a significant weightage in engineering entrance exams. Students who are looking for learning aids to prepare better for Class 11 Physics exam must refer to NCERT Solutions for Chapter 1 by Extramarks. Our NCERT solutions for Class 11 Physics Chapter 1 are prepared in the most simple and easy-to-understand language by a team of experienced teachers.


NCERT Solutions for Class 11 Physics Chapter 1 – Physical World 

The word Science is derived from the Latin verb ‘Scientia’ which means ‘to know.’ NCERT Class 11 Chapter 1 of Physics talks about how science has travelled and progressed from countries like India, Egypt, China, Greece, etc. Science became popular during the mid-twentieth century with great efforts to put it in a big way.  It makes them aware of how many experiments, systematic observations, etc play a vital role in learning about the world.  The chapter will make students familiar with complex theories, problems, and much more. Students can also prepare themselves for exams by keeping their basic concepts clear. 


In particular, students would learn about two principal thrusts in Physics 

  • Unification – The prime focus of unification is to unify the fundamental forces of nature. The example of gravity making things fall on the ground and also causing the motion of the moon around the earth can be used to understand the concept more precisely. 
  • Reduction – Reduction is the core concept of Physics. In this topic, the properties of simpler parts are used to derive the properties of a bigger and more complex system. 

Access NCERT Solutions for Physics Chapter 1 – Physical World

To get everything in one place and get complex problems solved in a well-structured and understandable way, students must refer to Physics Class 11 Chapter 1 NCERT solutions. They can download it for free from the website. 

NCERT Solutions for Physics Chapter 1 will make it convenient for students to manage their studies. They can prepare an effective schedule for studying the right subject at a specific time. 


NCERT Solutions for Class 11 Physics – Free Download

Students can download the NCERT Solutions for Class 11 Physics on their device, which saves them from the hassle of searching for reliable solutions and being dependent on the Internet to study Chapter 1.



Physics holds a good weightage in competitive exams as it deals with the basic study of Science, Mathematics, Natural Sciences, Forces, and more. In Class 11, students will get a basic understanding of the past and the development of laws in Physics. 


Scope and Excitement of Physics

The scope of Physics is concerned with the magnitude of physical quantities like energy, mass, etc. The three disciplines are Microscopic, Mesoscopic, and Macroscopic phenomena. 


Microscopic Phenomena 

The phenomenon takes place at the molecular or atomic level. 


Mesoscopic Phenomena

Mesoscopic Phenomena occur between the microscopic and macroscopic phenomena. Once we enforce miniature of the macroscopic level phenomena as wiped-out electronic Physics is applicable to this level of Physics. 


Macroscopic Phenomena 

The theories related to classical Physics are not applicable to Microscopic and Mesoscopic phenomena. 

  1. Mechanics – The study of Physics related to the behaviour of bodies and their effect on the environment when subjected to external mechanical force is understood as mechanics. E.g. Pushing a door or pulling a rope is a primary example of mechanical force. 
  2. Electrodynamics – The study of Physics related to the electrical and magnetic phenomena pertaining to the charged and magnetic bodies is often known as Electrodynamics. Response of electrical circuits to ac voltage(signal) or working of an antenna. 
  3. Optics – The study of Physics dealing with light-related phenomena is called optics. The issues associated with optical phenomena and instruments are covered in the topic.
  4. Thermodynamics – The situation that consists of macroscopic equilibrium and takes care of entropy charge, temperature, internal energy, etc of the system through external work and warmth transfer, is called Thermodynamics. It is not similar to mechanics as it does not deal with the motion of particles as an entire. The issues of interest in Thermodynamics are the efficiency of engines and refrigerators and the direction of physical-chemical processes. 


Excitement of Physics 

As a subject, Physics can turn out to be quite an exciting subject as it offers a basket of knowledge and learning. Many people find it exciting as the subject has a high potential in exciting people’s mentality. For some people, every problem poses its own challenge while many people might think that they will pose a huge magnitude of physical quantities with the help of a couple of basic principles. 

Excitement results in Progress – The excitement is the driving force for people and students to progress in the field of Physics. The excitement to explore new ways of understanding and learning Physics has made it an advance at such a faster pace. When a student solves a law, it gives him/ her thrilling work and increases their love for Physics more.  


Physics Technology and Society

Thermodynamics has eventually been used in later inventions like refrigerators, blowers, vehicles, etc. Physics has left its impression on society through technological advancements in these ways – 

  1. Energy Industry – The contributions of physicists like Faraday, Tesla, and Edison are immense to the commercialization of electricity. They were the ones who led the foundation of what today is called the age of globalization. They changed the way food was produced to the way people travelled from one place to another through the use of fossil fuels like petrol, diesel, and coal. They had a huge role to play and influencing it as an industry and developing it. The rising levels of pollution have forced people to shift to renewable energy sources. Dams, solar panels, wind farms, nuclear reactors – the energy of the future is highly dominated and influenced by the Physics of today. 
  2. IT Industry – Today, the IT industry is filled with an extensive proliferation of computers in our day-to-day lives which eventually has resulted in an increasing number of modern MNCs. Even here, the contribution of Physics is exceptional and it includes the once ancillary but now vital data processing and network speeds. 


Fundamental Forces in Nature

The forces that we see and use in our daily routine such as muscular, friction, forces are a few of the fundamental forces of nature. 

    1. Gravitational force – When there is a force of mutual attraction between two objects by virtue of their masses is called a universal force as the force is experienced by every other force in the universe. 
  • Electromagnetic Force – The force between charged particles is called Electromagnetic force. The charges at rest have electric attraction and repulsion. When in motion, they produce magnetic force. The combination of all these is known as the electromagnetic force. 
  • Strong Nuclear Force – A strong nuclear force is an attractive force between protons and neutrons in a nucleus. It acts equally between a proton and a proton, a neutron and a neutron, and also between a proton and a neutron. 


Nature of Physical Laws

This subject of Physics explores the universe. It involves a range of exploration like the smaller particles than the atoms in size to the stars that are very far away. Conserved quantities are those physical quantities that remain unchanged in a process. The laws of conservation of mass, energy, linear momentum, angular momentum, charge parity, etc are some of the general conservations. A law is considered to be good only if it explains the existing facts, predicts future results, stands the test of experimental verification and also the test of time. These laws have a deep connection with the symmetries of nature. The modern theories of fundamental forces in nature are largely established by the convention laws that have a deep connection with the symmetries of nature. 


Exercise 1.1

All the solutions that are explained and narrated in Class 11 Physics Chapter 1 Exercise 1.1 are prepared based on all the natural laws discussed. You can get all the solutions explained in detail in a systematic order. One needs a deeper understanding of the chapter and the team at Extramarks can give you further insights into it. 


Key Features of NCERT Solutions for Class Physics Chapter 1

A good solution set will have answers explained by expert teachers and ones who know what are the points that students need to tap in. The expert teachers possess years of experience in this subject. They have explained the solution sets in such a way that it will help students in adapting to solve any kind of question related to a particular topic. 

  • Easy way to recollect whatever you’ve learned in the chapter. 
  • Students will get good preparation material for exams. 
  • They can also remember formulas easily with various tips and tricks taught. 

Q.1 Some of the most profound statements of on the nature of science have come from Albert Einstein, one of the greatest scientists of all time. What do you think did Einstein mean when he said: ”The most incomprehensible thing about the world is that it is comprehensible’’?


Since the physical world has a wide variety of things and an amazing diversity of life, it appears incomprehensible i.e. as it cannot be understood. However, on an investigation, the scientists find that the laws governing physical phenomena from atomic and astronomical ranges are few and extremely simple. In this way, the physical world becomes comprehensible. This is meant by the above statement given by Einstein.

Q.2 Every great physical theory starts as a hear say and ends as a dogma. Give some examples from the history of science of the validity of this incisive remark.


The given statement is true. A long time ago, Ptolemy postulated that earth is stationary and all other heavenly bodies like sun, stars, planets etc. revolve around it. After that, Galileo suggested that sun is stationary and earth along with other planets is revolving around it. Galileo was punished by the authorities of that time for spreading wrong concepts. But, afterwards Galileo’s theory was supported by Newton and Kepler and now it is no more than a dogma.

Q.3 ‘Politics is the art of possible’. Similarly, ‘Science is the art of the soluble’. Explain this beautiful aphorism on the nature and practice of science.


It is common that in order to get votes, politicians would make anything and everything possible even when they are not sure of the same. The statement that science is the art of the soluble means that a few basic concepts can be used to understand a wide variety of physical phenomena i.e. it seems as if widely different phenomena are soluble and can be explained in terms of only a few fundamental laws.

Q.4 Though India now has a large base in science and technology, which is fast expanding, it is still a long way from realizing its potential of becoming a world leader in science. Name some important factors, which in your view have hindered the advancement of science in India.


Some important factors which have hindered the advancement of science in India are:

i. Poverty, which gives rise to a lack of resources and lack of infrastructure

ii. Lack of education and limited facilities for higher education in science

iii. Deficiency of scientific planning

iv. Pressure of increasing population of India

v. Lack of self discipline and work culture

Q.5 No physicist has ever “seen” an atom. Yet, all physicists believe in the existence of atoms. An intelligent but superstitious man advances this analogy to argue that ‘ghosts’ exist even though no one has ‘seen’ one. How will you refute this argument?


It is a fact that any physicist has never seen an atom. But, there is so much evidence that proves the atomic nature of matter. On the other hand, there is hardly any direct or indirect evidence to prove the existence of ghosts.

Q.6 The shells of crabs found around a particular coastal location in Japan seem mostly to resemble the legendary face of a Samurai. Given below are two examples of this observed fact. Which of these strikes you as a scientific explanation?
a. A tragic sea accident several centuries ago drowned a young Samurai. As a tribute to his bravery, nature through its inscrutable ways immortalized his face by imprinting it on the crab of shells in that area.
b. After the sea tragedy, fishermen in that area, in a gesture of honour to their dead hero, let free any crab shell caught by which accidentally had a shape resembling the shape of a Samurai. Consequently, the particular shape of the crab shell survived longer and therefore in course of time the shape was genetically propagated. This is an example of evolution by artificial selection.

[Note: This interesting illustration taken from Carl Sagan’s ‘The Cosmos’ highlights the fact that often strange and inexplicable facts which on the first sight appear ‘supernatural’ actually turn out to have simple scientific explanations. Try to think out other examples of this kind].


Explanation (b) given above is a scientific explanation of the observed fact.

Q.7 The industrial revolution in England and Western Europe more than two centuries ago was triggered by some key scientific and technological advances. What were these advances?


The discovery of steam engine, blast furnace (which converts low grade iron into steel) and cotton gin (which separates the seeds from cotton three times faster than by hand) and power loom are some of the examples of key scientific and technological advances.

Q.8 It is often said that the world is witnessing now a second industrial revolution, which will transform the society as radically as did the first. List some key contemporary areas of science and technology which are responsible for this revolution.


Some of the key contemporary areas of science and technology which are responsible for this revolution are:

i. Growth of superfast computers

ii. Advancements of semiconducting materials at room temperature

iii. Information explosion and development of information technology

iv. Development of digital electronics, robots and nanotechnology

v. Advancements in biotechnology

Q.9 Write in about 1000 words a fiction piece based on your speculation on the science and technology of the twenty second century.


Imagine a space ship travelling towards a star nearly 100 light-years away. Since the space ship crosses the magnetic fields in space, it is propelled by an electric current generated by electromagnetic induction. The current is provided to an electric motor made of superconducting wires. Therefore, energy would not be required to propagate the spaceship through its entire journey.

Suppose, in a particular region of the space the temperature becomes extremely high and the superconducting property of the wires of the motor is destroyed. Since no power will be generated by the motor, it will give rise to a panic in the spaceship.

In a fraction of a second, another space ship filled with matter and antimatter stored in different compartments to generate energy for the first spaceship comes to its rescue, and the first ship continues its progressive journey.

Q.10 Attempt to formulate your ‘moral’ views on the practice of science. Imagine yourself stumbling upon a discovery, which has great academic interest but is certain to have nothing but dangerous consequences for the human society. How, if at all, will you resolve your dilemma?


If any scientific discovery is academically extremely important, then it will surely have dangerous consequences as well. Therefore, it becomes the responsibility of the scientists to inform the ordinary people about the dangerous consequences of any discovery. For example, the discovery of nuclear fusion gave rise to the production of electric power, which is very useful for mankind. On the other hand, nuclear fusion is also used for the production of an atom bomb, which can be used for the destruction of the human race. Therefore, people should be educated on large scale to use nuclear energy for peaceful purposes only.

Q.11 Science, like any knowledge, can be put to good or bad use, depending on the user. Given below are some of the applications of science. Formulate your views on whether the particular application is good, bad or something that cannot be so clearly categorized:
a. Mass vaccination against small pox to curb and finally eradicate this disease from the population. (This has already been successfully done in India).
b. Television for eradication of illiteracy and for mass communication of news and ideas.
c. Prenatal sex determination.
d. Computers for increase in work efficiency.
e. Putting artificial satellites into orbits around the earth.
f. Development of nuclear weapons.
g. Development of new and powerful techniques of chemical and biological warfare.
h. Purification of water for drinking.
i. Plastic surgery.
j. Cloning.


a. Mass vaccination is a good application of science.

b. Television is good for eradication of illiteracy and it is a good method of mass communication and entertainment as well.

c. Since prenatal sex determination leads to the practice of abortion of female foetus, therefore, it is bad. It is creating imbalance between the male and female population, therefore, people must be educated to avoid it.

d. Computers are useful for increasing work efficiency.

e. Putting artificial satellites into orbits around the earth is good for mankind.

f. Since the development of nuclear weapons can lead to destruction of mankind, therefore, it is bad for human race.

g. Since the development of new and powerful techniques of chemical and biological warfare can lead to destruction of mankind, therefore, it is bad for human race.

h. Purification of water is useful for drinking.

i. Since plastic surgery helps to remove certain type of deformations in needy persons, therefore, it is a good application of science.

j. Cloning is a good application of science.

Q.12 India has had a long and unbroken tradition of great scholarship-in mathematics, astronomy, linguistics, logic and ethics. Yet, in parallel with this, several superstitious and obscurantistic attitudes and practices flourished in our society and unfortunately continue even today-among many educated people too. How will you use your knowledge of science to develop strategies to counter these attitudes?


People should be educated to eliminate superstitious and obscurantistic attitudes. It is possible with the development of the school and college curricula suitably. In this way, the teachers can take this responsibility. The mass media like radio, television, newspapers, magazines, etc. can also be very useful to educate the common people so that the superstitious and obscurantistic attitudes can be eliminated.

Q.13 Though the law gives women equal status in India, many people hold unscientific views on a woman’s innate nature, capacity and intelligence and in practice give them a secondary status and role. Demolish this view using scientific arguments, and by quoting examples of great women in science and other spheres; and persuade yourself and others that, given equal opportunity, women are on par with men.


If equal opportunity is given, women are at equality with men in every field. The basic factor responsible for the development of the human mind is the nutrition content of the prenatal and postnatal diet. The development of the human mind also depends on the care and use of the mind. Gender discrimination does not play any role in this case. Examples of great women in science and other spheres are:

Madam Marie Curie who won the Nobel Prize in Physics, Mrs. Margaret Thatcher, Mrs. Indira Gandhi, and Mrs. Bhandarnaike excelled others in politics.

Q.14 “It is more important to have beauty in the equations of Physics than to have them agree with experiments”. The great British physicist P. A. M. Dirac held this view. Criticize this statement. Look out for some equations and results in this book which strike you as beautiful.


The view held by the great British physicist P. A. M. Dirac is partially false. For example: E = mc2; F = ma are some of the simple equations of Physics which are having universal application as well.

On the contrary, the equations involved in some of the latest works of higher Physics and the general theory of relativity are neither simple nor beautiful. They are comparatively difficult to understand.

Though the statement quoted above may be disputed, most physicists do have a feeling that the great laws of Physics are at once simple and beautiful. Some of the notable physicists, besides Dirac, who have articulated this feeling, are: Einstein, Bohr, Heisenberg, Chandrasekhar and Feynman. You are urged to make special efforts to get access to the general books and writings by these and other great masters of physics.

General books on Physics make interesting reading, so the students are advised to confer a good library.

For example- ‘Mr. Feynman’ by Feynman is one of the amusing books for the students.

Some other amusing books are: Physics, Foundations and Frontiers by G. Gamow; Thirty years that shook Physics by G. Gamow; Physics for the enquiring mind by EM Rogers; Physics can be fun by Parelman.

Textbooks on science may give you a wrong impression that studying science is dry and all too serious and that scientists are absent-minded introverts who never laugh or grin. This image of science and scientists is patently false. Scientists, like any other group of humans, have their share of humorists, and many have led their lives with a great sense of fun and adventure, even as they seriously pursued their scientific work. Two great physicists of this genre are Gamow and Feynmann. You will enjoy reading their books listed in the Bibliography.

Scientists like other people of the human race are lively, fun loving, friendly, and adventurous people. Students are advised to go through books by the given Physicists to understand this view.

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FAQs (Frequently Asked Questions)

1. Can one prove everything with the help of Physics and Mathematics?

It is not advisable for anyone to think that physics or mathematics can prove everything because these are based on Science and Science is based on assumptions. These assumptions might be true only to a certain extent hence it can’t be said that everything can be proved through physics and mathematics. 

2. Is referring to NCERT solutions necessary for students?

We highly recommend students to refer to NCERT Solutions as the chapters are explained by experienced teachers in a simple manner. It will help students manage their time during exams and create a timeline for solving questions in the exams in a systematic way. 

Apart from these, our focus is to provide all the study materials to students in the simplest of forms hence, we also have NCERT solutions, NCERT solutions class 1, NCERT solutions class 2, NCERT solutions class 3, NCERT solutions class 4, NCERT solutions class 5, NCERT solutions class 6, NCERT solutions class 7, NCERT solutions class 8, NCERT solutions class 9, NCERT solutions class 9, NCERT solutions class 10, NCERT solutions class 11 and NCERT solutions class 12.