Important Questions Class 12 Chemistry Chapter 4
Science basically consists of Physics, Chemistry and Biology. Understanding all the concepts implicit in these subjects is critical for students to perform well academically. Science is a very essential part of human life. Science teaches students to think analytically. The significance of learning Science is not to tell someone what to think. It teaches one to think. In scientific research, one learns how to analyse vast amounts of data. As a result, students have the opportunity to learn how to identify appropriate data in particular contexts, and what needs to be investigated further. This type of analytical thinking is important for learning many other academic disciplines.
The knowledge of Science teaches how to solve problems. The application of concepts embedded in Science can be useful when a person faces a problem. Science has many advantages for young students. At a young age, students acquire many skills that they will need later in their academic careers. People benefit from science in many ways, including having clear communication capabilities, developing strong focus, and creating good organisational skills. Studies indicate that a student generally becomes interested in STEM only in elementary school. Encouraging this interest helps students build confidence with regard to the learning of scientific disciplines and increases the professional and educational opportunities available to them.
Science can help people in their daily lives. The relationship between scientific progress and the extension of the human lifespan is clear. Without knowledge of germs and effective treatments, humans were very vulnerable in the past. In Europe, the average life expectancy of a person between the ages of 1500 and 1800 was 30 to 40 years. In 2019, the average life expectancy of people in Europe increased to around 80 years. There are many reasons for this increase – including better diets and better drugs – but they are all related to Science in some way.
The knowledge of Science is helping to reduce child mortality. Everyone knows how people used to be very vulnerable, but the reality is that they are still vulnerable in many ways. There are still many reasons why children do not grow up, such as poverty and disease. In 2019, WHO calculated that more than 5 million children under the age of 5 died, mostly from preventable and treatable causes. Owing to the knowledge of Science, experts can identify causes (such as waterborne diseases and malnutrition) and work to change the situation. Science also helps doctors learn more about childhood cancer and other threats to children’s lives.
The knowledge of Science has led to the development of the technology people use every day. Science is not limited to the study of nature, disease, or human longevity. Without the knowledge of Science, there would be no technology like computers, the internet, or cars. These inventions have changed the way people live in this world, the way people travel, the way everyone communicates, and the way they learn. These inventions are enabling new scientific discoveries and innovations such as artificial intelligence, space exploration, and DNA sequencing.
The knowledge of Science can help combat climate change. Climate change threatens the future of the planet. Its effects are evident in the contemporary era: severe droughts, uncontrolled wildfires, and even more powerful hurricanes. Scientific knowledge tells humans how to stop the progress of climate change. Financing renewable energy sources, reducing fossil fuel emissions, and making transportation more efficient are all necessary changes that need to be incorporated into daily human life.
Scientific knowledge can be beneficial for solving the mysteries of the universe. There are many things people do not know about the universe they call home. Even if they overcome the belief that the earth is flat or that the sun revolves around them, ignorance is still prevalent in society. Scientific research is helping people glean more information about the origin of the universe, ideas about black holes, extraterrestrial life, and even the multiverse.
The academic field of Science can be perceived as an exceptionally lucrative professional arena. There are many fields where knowledge of Science can be applied, such as Medicine and Computer Science. Some careers can be reached with just a bachelor’s degree, but the highest-paying jobs usually require further educational qualifications.
The NCERT Solutions for Class 9 Science Chapter 11 inHindi will help lay a good conceptual foundation for CBSE exam preparation. Students who regularly peruse the NCERT Solutions for Class 9 Science Chapter 11 inHindi benefit from the comprehensive solution methodology and detailed step-by-step instructions for performing well on the Science examination.
The benefits of NCERT Solutions for Class 9 Science Chapter 11 inHindi for CBSE board exams are numerous. The NCERT Solutions for Class 9 Science Chapter 11 inHindi are the perfect choice for students as these solutions encapsulate all the solutions for the exercises of Chapter 11. The NCERT Solutions for Class 9 Science Chapter 11 inHindi have been developed while keeping the CBSE curriculum in mind. The NCERT Solutions for Class 9 Science Chapter 11 inHindi provide students with in-depth knowledge of any subject, topic, and concept that is a part of Chapter 11 Class 9 Science so that they can learn more effectively. Direct and indirect questions from the prescribed NCERT textbooks are also included in the CBSE Board exam question papers. The Central Board of Secondary Education administers the board exams for classes 10 and 12. Therefore, students must have relevant and quality academic materials available for reference at their convenience.
The NCERT Solutions for Class 9 Science Chapter 11 inHindi would help students practice on a regular basis for examination preparation and boost their confidence. Thoroughly prepared by subject matter experts of Science of Extramarks, all these NCERT Solutions for Class 9 Science Chapter 11 inHindi include tips for examination preparation and efficaciously sequenced short and long questions to help students with both the CBSE exam and competitive exams.
NCERT Solutions for Class 9 Science Chapter 11 Work and Energy in Hindi PDF Download
All the solutions to Class 9 Science Chapter 11 in Hindi are available on the Extramarks educational portal. Class 9 students studying Science using NCERT textbooks would come across Chapter 11, titled Work, Power and Energy. After learning the lesson, students will have to look for answers to the questions enclosed in the exercises. Students can access complete NCERT solutions for Class 9 Science Chapter 11 Work, Power and Energy in one place. To better understand this chapter, students must cautiously read Class 9 Science Chapter 11 Solutions inHindi.
The NCERT Solutions for Class 9 Science Chapter 11 inHindi involve brief explanations of the concepts of Work and Energy. The NCERT Solutions for Class 9 Science Chapter 11 inHindi provide insight into the concept of Work and how “work” is defined in daily life. Students can examine some illustrative examples through the subtopics mentioned below to learn more about the work.
The NCERT Solutions for Class 9 Science Chapter 11 inHindi provide students with insight into crucial themes with the aid of exceptional working examples. An important example provided in the NCERT textbook of Science is the narrative of Kamali. Kamali has to prepare for exams. She diligently follows the schedule and revises for exams whenever she can. She organises, analyses and maps thoughts, thereby collecting research material suitable for study. As is evident, all the activities that Kamali does require enough energy. In common parlance, Kamali works hard. In short, the definition of work varies from person to person. The scientific concept of work does not include activities that have an impact after work, both for the subject and object. In accordance with the scientific explanation of work, the NCERT Solutions for Class 9 Science Chapter 11 inHindi address different situations.
From a scientific point of view, work can be defined as pushing a pebble lying on a surface, lifting a book from a corresponding height, and so on. So, for job two to be performed, two conditions need to be met. These include the effect of force on an object and the displacement of that object. Students must have wondered how work is defined by Science. This can be easily understood by a simple demonstration as follows. For example, students could consider a situation where the force is acting in the direction of the displacement. Further, they could consider a constant force F acting on a particular object. Let this object be rendered by a specific distance S in the exact direction of the force. Here:
Work done = Forcex Displacement
W = Fs
Students could refer to NCERT Solutions for Class 9 Science Chapter 11 in Hindi to learn more about these concepts.
Students must now understand that energy is necessary for life itself. The demand for energy seems to be increasing disproportionately. However, a question arises about where that energy comes from. The sun is the largest natural energy source for living things. Solar energy is one of the most common sources of energy. In addition, energy can be extracted from atomic nuclei, tides, and the interior of the earth. There are innumerable forms of energy. The world offers energy in myriad forms. These include potential energy + kinetic energy (mechanical energy), light energy, chemical energy, electrical energy and thermal energy
- Kinetic energy
The kinetic energy of a given object is nothing but the energy produced by its motion. This is known as the work required to accelerate a mass from rest to its actual velocity.
- Potential energy
The energy possessed by each object mainly due to changes in shape and position is called potential energy.
- The Potential Energy of a body at a height
When an object is lifted to a height, its energy increases. This is due to the fact that when an object is lifted against gravity, they are working on it. The gravitational potential energy of an object is the amount of energy that is available within it in this situation.
Students must read NCERT Solutions for Class 9 Science Chapter 11 inHindi to understand how energy conversion to different forms occurs.
- Law of Conservation of Energy
The Law of Conservation of Energy states that energy can only be converted from one form to another. It cannot be created or destroyed. The sum of energies before and after transformation is always constant. Power is primarily defined as the overall speed of work performance. The SI unit of power is defined as watts.
1Watt = 1Joule/second
- The trading unit of energy
A joule is such a small unit that it is unreliable to define a definite and large amount of energy. For this reason, a larger unit called the kilowatt hour (kWh) is used. Energy accessed at a rate of 1 kW in approximately one hour is known as 1 kWh.
Access NCERT Solutions for Class 9 Science Chapter 11- कार्य तथा ऊर्जा
The NCERT Solutions for Class 9 Science Chapter 11 inHindi are vital learning assets which can prove to be an essential part of the learning process of Science. Work and energy are closely related terms that are prevalently relevant to people’s daily lives. In the designated chapter, students will learn more about themes such as Work, Force, and Energy and how they are related. The NCERT Solutions for Class 9 Science Chapter 11 inHindi contain comprehensively solved problems and everyday examples to help students study the subject effectively. Key Features of the NCERT Solutions for Class 9 Science Chapter 11 inHindi are as follows:
- The NCERT Solutions for Class 9 Science Chapter 11 inHindi provide detailed explanations for all complex concepts.
- The NCERT Solutions for Class 9 Science Chapter 11 inHindi provide fully resolved solutions to all questions contained in the Class 9 Science NCERT textbook for Chapter 11.
- The NCERT Solutions for Class 9 Science Chapter 11 inHindi include some key questions at the end of each chapter
- The language used in NCERT Solutions for Class 9 Science Chapter 11 inHindi is simple and easy for students to understand.
- All of these NCERT Solutions for Class 9 Science Chapter 11 inHindi are prepared by subject matter experts after extensive research on each topic to provide students with relevant and reliable information.
NCERT Solutions for Class 9 Science Chapter 11 Work and Energy in Hindi
“Practice” in the broadest sense is simply an activity that is repeated regularly. Sometimes people consciously repeat an activity. Some activities are done consciously but some activities can be done unconsciously like walking and cooking. Whether students realise it or not, students practice all the time. Practising is very important. Even when students are not actively engaged in a learning activity, their brain continues to absorb and learn. Even in their spare time students are constantly learning. So students can also make the most of their time and practice effectively. Focus is the key to learning and growing. Focusing on what students want to learn and improving is the best way to practice effectively. By focusing on their academic goals during learning, students can make better use of their time and learn faster.
It is noteworthy that it is so important to practice effectively. Effective practice means actually going in the academic direction students want to go and doing it in a relatively efficient way. This means students need to determine goals and actively strive to attain them. These goals can be as small as a specific ability. Otherwise, it can be a large image target. Setting goals and working hard to reach those goals maximises their time and efficiency, and ultimately gives students the best chance of achieving those goals. Therefore, practising is the key to success and students should practice the exercises provided in their NCERT textbooks with a focused mind.
The NCERT books are not only sufficient to cover the entire CBSE syllabus, but also all the basics and foundations of any subject in simple and easy language. Once their understanding of concepts is clear, students can proceed to further chapters. All students have to do during the exam is revise formulas, terminologies and their applications for solving various kinds of problems. For this reason, the NCERT textbooks are considered ideal for thorough and comprehensive research to develop clear concepts. Class 9 Science Chapter 11 Question Answer inHindi can be helpful for students who want to practice the solutions.
If students go through past years’ papers, they will observe that most of the questions asked in the question papers came directly or indirectly from the NCERT textbook. In fact, the NCERT Solutions for Class 9 Science Chapter 11 inHindi are accompanied by learning resources such as sample papers and question banks on the Extramarks e-learning portal. CBSE often asks complex and lengthy questions in board exams. However, it should be understood that studying the NCERT books requires clarifying concepts and learning how to apply them. It is important to read and study these books carefully and solve them with the assistance of NCERT Solutions for Class 9 Science Chapter 11 inHindi. The NCERT Solutions for Class 9 Science Chapter 11 inHindi provide step-wise solutions to all the exercises accompanying Chapter 11.
Students can enhance their academic performance with the aid of NCERT Solutions for Class 9 Science Chapter 11 inHindi available on the Extramarks educational website. These exercises consist of short-answer and long-answer questions, matching questions, or fill-in-the-blank questions. Therefore, it is very important for students to practice different questions in order to get the best grades in board exams. In addition to these practice questions, it is also important to practice NCERT Solutions for Class 9 Science Chapter 11 inHindi. This allows students to comprehend all kinds of challenging questions.
Chapter-by-chapter NCERT solutions are provided on the Extramarks learning platform along with the NCERT Solutions for Class 9 Science Chapter 11 inHindi to help students gain a comprehensive understanding. The NCERT Solutions for Class 9 Science Chapter 11 inHindi have been prepared by subject specialists of Science of Extramarks considering the comprehension abilities of all types of candidates. The NCERT Solutions for Class 9 Science Chapter 11 inHindi are designed to give each concept a solid academic foundation. The NCERT Solutions for Class 9 Science Chapter 11 inHindi will give students a smooth understanding of all the concepts including advanced concepts explained in the textbook. The PDF download option of NCERT Solutions for Class 9 Science Chapter 11 inHindi are easily available on the Extramarks website and mobile application. When students visit the website, students will be required to register by giving basic details on the website. Students can then download all of the selected learning materials conveniently and efficiently. The NCERT Solutions for Class 9 Science Chapter 11 inHindi can also be downloaded from the Extramarks Learning App.
The NCERT Solutions for Class 9 Science Chapter 11 inHindi take into account the needs and concerns of students studying in Hindi Medium educational institutions These NCERT Solutions for Class 9 Science Chapter 11 inHindi are written in a simple and easy manner to understand language which gives students many benefits. The best feature of these solutions is that they are easy to download. Class 9 students can download NCERT Solutions for Class 9 Science Chapter 11 inHindi very conveniently for self-guided learning.
Remarkably, the NCERT Solutions for Class 9 Science Chapter 11 inHindi are a compilation of all the answers to the textbook exercises. The answers/solutions inculcated in NCERT Solutions for Class 9 Science Chapter 11 inHindi are organised in a step-by-step format and are very well-researched by highly qualified mentors with relevant experience in the field. In short, NCERT Solutions for Class 9 Science Chapter 11 inHindi are very helpful for examination preparation, and quick review before the annual exams. Extramarks also provides Class 9 Science Chapter 11 Notes inHindi for quick revision of the chapter.
FAQs (Frequently Asked Questions)
1. What topics are covered in NCERT Solutions for Class 9 Science Chapter 11 inHindi?
Topic weightage pertaining to NCERT Solutions for Class 9 Science Chapter 11 inHindi is as follows:
- 5 questions (3 long, 2 short) of work
- 1 question (1 short) of energy
- One Question (1 MCQ) of the unit of energy
- One Question (1 MCQ) of forms of energy
- 1 question (1 short question) about kinetic energy and applications
- 1 Question (1 Short) of potential energy and application
- 1 question (1 short) on energy conservation
2. What is the kinetic energy of an object in NCERT Solutions for Class 9 Science Chapter 11 inHindi?
The kinetic or mechanical energy of an object is the energy that an object has due to its motion. All objects that move have mechanical energy. The body tries to work using mechanical energy. Students can easily grasp this concept with the help of NCERT Solutions for Class 9 Science Chapter 11 inHindi created by Extamarks. The NCERT Solutions for Class 9 Science Chapter 11 in Hindi also include comprehensive instructions to help the student prepare for the CBSE annual exams.
3. Can a student rely fully on Extamarks' NCERT Solutions for Class 9 Science Chapter 11 inHindi?
Extramarks’ NCERT Solutions for Class 9 Science Chapter 11 in Hindi are primarily aimed at helping students focus on key concepts and are holistically designed as every detail is explained with full accuracy to enhance students’ conceptual knowledge. The NCERT Solutions for Class 9 Science Chapter 11 inHindi also include various efficient techniques that can be used to effectively retain vital concepts. When answering textbook questions, students can refer to the NCERT Solutions for Class 9 Science Chapter 11 inHindi.