CBSE Class 11 Physics Revision Notes Chapter 1

Class 11 Physics Revision Notes for Chapter 1 – Physical World

Physics involves the study of the basic laws of nature and the interactions between different matter. With Physics, not only exam oriented learning but understanding the history of the subject and various recent developments is also equally important.   Chapter 1 of Class 11 Physics provides an introduction to Physics and its multidisciplinary nature. 

Students must read and understand Physics for all tests, including those at the upper secondary level, as it is required for many competitive exams. They can understand these ideas more quickly and have a less stressful learning experience with the help of the CBSE Class 11 Physics Chapter 1 Notes.

Revision Notes for Class 11 Physics Chapter 1 – Physical World – Free Download

Access class 11 physics Chapter 1- Physical World Notes

Science and its origin:

Originating from the Latin verb Scientia, ‘To Know,’ the term Science can be applied to the systematic understanding of natural phenomena in a detailed manner to predict, control and modify them. Acquiring knowledge in science can be done in-depth by:

• Systematic observations 
• Controlled observations
• Qualitative and Quantitative reasoning
• Mathematical modelling
• Speculation or Prediction

Observations in science are made using tools that allow a refined perspective on theories, like the usage of Tycho Brahe’s research on planetary motion, by Johannes Kepler to better the Nicolas Copernicus theory.

Natural Sciences:

Comprehension of the description, prediction and understanding of a natural phenomenon based on observational and empirical evidence is called Natural Science. Physics, Chemistry and Biology are natural sciences. 

Physics:

Physics is the study of the basic laws of nature and the physical world with correlation to matter and its movement through space and time. The origin of the term ‘Physics’ is the Greek word ‘Phusike’ meaning ‘Nature’. 

The two approaches in physics are 

1. Unification is a method of collective inclusion of all phenomena in nature under various domains and conditions into a group of universal laws. Eg. The Law of Gravitation is applied universally. 
2. Reduction is a method wherein properties and interactions between parts of complex systems can be used to derive their characters as a whole. Eg. Temperature studies under thermodynamics may be connected to the kinetic energy of molecules. 

Effects of physics would include :

1. The ability to explain phenomena over larger magnitudes
2. New theories may be found and old theories may be improved
3. New devices can be developed for human use.

Scope of Physics:

Physics shows ample scope in many areas of its understanding as well as application. Quantities like length, time and mass range from a wide variety of values to provide proof to support this claim of the scope of physics. 

Based on its scope, Physics can be divided into Classical and Modern Physics. 

• Classical Physics deals with the macroscopic phenomena
• Modern Physics deals with microscopic phenomena

Microscopic Domain

The atomic, molecular and nuclear scales of physics come under the microscopic domain and explore various topics related to the interaction of electrons, photons and the Quantum theory.

Improvement of Physics must be done to :

• Provide qualitative and quantitative analysis in collaboration
• Enunciate applications of universal laws
• Provide basic laws to understand complex phenomena
• Focus on important theories related to different physical occurrences

Hypothesis, Axiom and Models:

Three concepts are explored below :

• Hypothesis: The act of supposing that something is correct, without assuming. Hypotheses can be cross-checked by applying them to a series of experiments. 

• Axiom: If no controversy or question is raised, and self-evident truth is accepted, it is an Axiom.

• Model: A model is used to represent observed phenomena, in the form of theories. 

• Assumptions: These are a crucial part of physics experiments, observations and statistical data. These allow the explanation of many phenomena. 

Technological Applications of Physics:

Physics became the scientific field it is now because of the inventions made in the past.

Some of those are given below 

• The industrial revolution’s invention of the steam engine.
• Discovery of wireless communication and the laws of electricity and magnetism
• Hahn and Meitner are credited with the creation of nuclear reactors and nuclear weapons in 1938 through the neutron-induced fission of uranium.
• Creation of energy from the sun, the wind and the earth.

Conserved Quantities:

Physical quantities known as conserved quantities do not alter throughout time. When a body is subject to an external force, its mechanical energy remains constant. However, the kinetic and potential energy of a single person could alter over time. These quantities could either be scalar (energy-containing) or vector (having total linear momentum and total angular momentum).

Conservation Laws:

Conservation laws are those laws which cannot be proven and remain hypotheses along with certain observations and experiments. 

Law of Conservation of Energy:

• According to this law, energies simply change from one form to another but do not change throughout time.
• The universe’s overall energy level remains constant.
• Symmetrical results can emerge at various periods and under similar circumstances.

Law of Conservation of Mass:

During the analysis of chemical reactions, this law holds importance.

• A chemical reaction shows the rearrangement of atoms among molecules, interactions within which provide a heat difference.
• Based on these differences, reactions can be called exothermic or endothermic. 
• The law affirms that the summation of the mass of reactants is equivalent to the mass of the products in a given chemical reaction. 
• Einstein’s theory E = mc2 provides a correlation between mass (m) and energy (E), c being the speed of light in a vacuum. 

Law of Conservation of Linear Momentum:

The Law of Linear Momentum results from translating the natural laws into their symmetrical versions in space. Even though the values of g differ between the earth and the moon, the Law of Gravitation stays the same on both bodies (acceleration due to gravity).

Law of Conservation of Angular Momentum:

Isotropy of space (no intrinsically preferred direction in space) underlies the law of conservation of angular momentum.

Physics Notes Class 11 Chapter 1 Physical World – An Overview of the Chapter

Class 11 Chapter 1 Physical World Revision Notes provided by Extramarks summarise all the topics in an effective manner. The students can refer to these notes for quick revisions and to conceptually understand the chapter and the topics involved in it. A concise overview of Class 11 Chapter 1 Physical World allows students to revise the entire portion efficiently in ample time. Formulated by subject matter experts, these notes mention all necessary pointers that help in answering questions related to Class 11 Chapter 1 Physical World. Students can easily access these notes and boost their exam preparation. 

What are the Different Concepts Covered in Physics Chapter 1 Class 11 Notes?

A concise introduction to Physics, its applications, and a short introduction to various laws and discoveries are uncovered in this chapter. The Extramarks revision notes for Class 11 Chapter 1 Physical World includes the most crucial topics present in the chapter. Therefore, students can add Extramarks Revision notes for Class 11 Chapter 1 Physical World to improve their exam strategy and perfect their revisions. 

Below Are the Basic Concepts That Are to Be Covered in the Notes of Chapter 1 Physics Class 11:

• Introduction to Physics 
• The approaches involved in Physics
• Future scope of Physics
• Advancing technology and its impact on the society
• Basics of the laws of nature (Gravitational, Nuclear forces, Electromagnetic forces)
• Concept of Conservation laws

Chapter 1 Physics Class 11 Notes

Multiple topics based on Class 11 Chapter 1 Physical World are explored in Extramarks Revision notes. 

Physical World

The understanding of the world around us, with its complexities and physicalities of it, defines the physical world. 

An honest attempt at solving these complexities leads to a new physical world.

How Will You Define Physics?

Physics is the science dealing with surroundings, nature and natural phenomena, discovered by Aristotle in 350 BC. A study of nature and the occurrences around us define the applications of various laws in physics. 

What are Science and Scientific Methods?

Scientific methods include the observations, experiments and verifications associated with several theories put forward in nature. A series of processes like reasoning, predictions and mathematical modelling can help prove many hypotheses. 

What is the Scope of Physics?

As the subject revolves around occurrences and circumstances taking place in nature, it has a vast scope. A never-ending questionnaire about the rules of nature, the universe and galaxies provides a challenge to the evolving human brain. Scientists discover new concepts every day to understand both macroscopic and microscopic aspects of physics. 

Relation of Physics to Other Subjects

Physics is an interdisciplinary subject which has relations with many other sciences. 

• Physics with Mathematics – The base of calculations in Physics is provided by mathematical concepts like calculus (integration and differentiation)

• Physics with Chemistry – Many laboratory techniques like X-ray and radioactivity are common to both Chemistry and Physics. In Chemistry, these techniques may be used to differentiate elements in the periodic table. 

• Physics with Biology – Biological processes require the applications of basic concepts of physics like calculation of blood pressure, diagnosis of diseases using X-rays etc. 

• Physics with Astronomy – The study of various stars using concepts involving light is a crucial part of many applications in astronomy. The use of optical telescopes is considered an example. 

• Physics with Meteorology – Weather forecasting methodologies involve the use of physical concepts like Pressure. 

Society and Advancing Technology 

New inventions and discoveries in the field of Physics open new doors of opportunity to a larger level of research. In various areas of research, the evolution of science and technology has shaped excellent applications of the learnings taken from physics. A few examples are the use of lasers in surgery, evolved methods of transportation and certain areas of communication. 

Forces in Nature

The four fundamental forces are Gravitational force, Electromagnetic force, Nuclear force and Weak forces. 

Conservation Laws

The laws of conservation revolve around the necessity of the equivalence of the reactants before the physical or chemical reaction to that of the products. If a ball is divided into many pieces, the mass of the ball equals the collective mass of the pieces referred to as the conservation of mass. 

Prominent Features to Study Extramarks Class 11 Chapter 1 Physics Notes 

Students need to build a solid conceptual foundation for the Higher Secondary education system as most of the subjects in Class 12 are based on the Class 11 curriculum.  A good preparation strategy for exams is a mark of a good student. Concise and carefully organised, the revision notes offered by Extramarks are sure to seep into the students’ minds during revisions. The notes for Class 11 offered by Extramarks will boost students’ confidence in answering questions. 

Conclusion

The first step to winning a battle is to prepare your mind. Therefore, students should plan ahead and acquire relevant materials that are easy to understand to stand out. The well-structured Revision Notes for  Class 11 Chapter 1 Physics from Extramarks give all-around support to exam preparations. It is easily accessible and provides an overview of all the topics in the chapter, making it easy for students to memorise important concepts.