General Q&A for Class 12 · Page 25
5,215 free answers in General for Class 12 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- GeneralClass 12All
What is machine learning?
Machine learning is a branch of artificial intelligence (AI) and computer science which focuses on the use of data and algorithms to imitate the way that humans learn, gradually improving its accuracy. It's a method of data analysis that automates analytical model building. By using algorithms that iteratively learn from data, machine learning allows computers to find hidden insights without being explicitly programmed where to look. Key aspects of machine learning include: <s
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What is the greenhouse effect?
The greenhouse effect is a natural process that warms the Earth’s surface. It occurs when certain gases in the Earth's atmosphere trap heat from the Sun. These gases allow sunlight (solar radiation) to pass through the atmosphere freely, where the Earth's surface absorbs it and then radiates it back as heat (infrared radiation). Some of this heat is trapped by greenhouse gases in the atmosphere, keeping the Earth at a temperature that is conducive to life. Without the greenhouse effect,
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What is a database management system?
A Database Management System (DBMS) is software that provides a systematic way to create, retrieve, update, and manage data in a database. It ensures that data is consistently organized and remains easily accessible. DBMSs serve as an interface between the database and its users or other application programs, simplifying how data is stored, managed, and retrieved. Key aspects and functionalities of a DBMS include: Data Management: It allows users to create, re
- GeneralClass 12All
What is acid rain?
Acid rain refers to a form of precipitation that is unusually acidic, meaning it has elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx), which react with the water molecules in the atmosphere to produce acids. The key aspects of acid rain include: Formation: The primary sources of the sulfur dioxide and nitrogen oxides
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What is the green revolution?
The Green Revolution refers to a set of research, development, and technology transfer initiatives that occurred between the 1940s and the late 1960s, which significantly increased agricultural production worldwide, particularly in developing countries. The term "Green Revolution" was first used in 1968 by former USAID director William Gaud. This revolution played a crucial role in ensuring food security and alleviating hunger in many parts of the world. Key aspects of the Green Revolution in
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What is a body count?
The term "body count" refers to the total number of people killed in a particular event or over a period, especially in the context of wars, conflicts, or disasters. It's used to quantify the number of deaths resulting from such incidents. The usage and context of this term can vary: Military Context: In military terms, body count is often used to describe the number of enemy combatants killed in a battle or conflict. It was a term widely used during the Vietnam War b
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What is a disaster?
A disaster is a serious disruption occurring over a relatively short time, affecting the functioning of a community or a society and causing widespread human, material, economic, or environmental losses that exceed the ability of the affected community or society to cope using its own resources. Disasters can be natural, man-made, or a combination of both. They are characterized by their suddenness, scale, and severity of impact. Natural Disasters: These are caused by
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What is environmental pollution?
Environmental pollution refers to the contamination of the Earth's environment with materials that interfere with human health, the quality of life, or the natural functioning of ecosystems (living organisms and their physical surroundings). Pollution often arises from human activities and has detrimental effects on the environment. It can occur in various forms and can affect different environmental components: Air Pollution: This involves the release of pollutants i
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What is a simple pendulum?
A simple pendulum is a fundamental and classic example in physics, representing a hypothetical model used to describe the motion of a pendulum in an idealized scenario. It consists of a weight (or bob) suspended from a fixed point by a string or rod that is weightless and inextensible. When the bob is displaced from its equilibrium position and released, it swings back and forth under the influence of gravity, demonstrating periodic motion. Key characteristics and properties of a simp
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What is Archimedes principle?
Archimedes' Principle is a fundamental law of physics discovered by the ancient Greek mathematician and inventor Archimedes of Syracuse. It pertains to the buoyancy of objects when placed in a fluid (which could be a liquid or a gas). The principle can be stated as follows: "When a body is immersed in a fluid, it experiences an upward force that is equal to the weight of the fluid displaced by the body." This principle has several important implications and applications:
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What is nitrogen fixation?
Nitrogen fixation is a process in which nitrogen gas (N₂) from the atmosphere is converted into ammonia (NH₃) or related nitrogenous compounds in soil. Atmospheric nitrogen, which makes up about 78% of the air, is relatively inert and cannot be used directly by plants. Nitrogen fixation is a crucial part of the nitrogen cycle, a natural process that makes nitrogen available to organisms that need it to survive and grow. There are several ways in which nitrogen fixation occurs: <p
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What are the three types of authentication?
Authentication is a process used to verify the identity of a user or a system. In the context of information security, there are generally three recognized types of authentication factors, often referred to as the "three factors of authentication." These are: Something You Know (Knowledge Factors): This is the most common form of authentication and includes things like passwords, PINs (Personal Identification Numbers), and security questions. The user must know and pr
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What is food preservation?
Food preservation refers to the process of treating and handling food in such a way as to stop or greatly slow down spoilage (caused or accelerated by microorganisms) and prevent foodborne illness while maintaining nutritional value, texture, and flavor. The primary objective of food preservation is to increase the shelf life of food while ensuring its safety and quality. Various methods are used for this purpose, each with its own techniques and benefits. Here are some common methods of food
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What is breakdown voltage?
Breakdown voltage, also known as dielectric strength, is a critical concept in the field of electrical engineering and physics. It refers to the minimum voltage that causes a portion of an insulator (such as air, solid, or liquid insulating material) to become electrically conductive or 'break down.' Here are some key points about breakdown voltage: Definition: Breakdown voltage is the voltage at which an insulator starts to conduct electricity. This happens w
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What is PCOS?
Polycystic Ovary Syndrome (PCOS) is a common health condition that affects women of reproductive age. It is characterized by a combination of symptoms and clinical signs, and its exact cause is not fully understood. However, it's believed to involve a combination of genetic and environmental factors. Key features and symptoms of PCOS include: Irregular Menstrual Cycles: Women with PCOS often experience irregular periods. This can mean infrequent periods (fewer than ei
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Who is the Indian legend regarding the discovery of tea?
The Indian legend regarding the discovery of tea is associated with the Buddhist monk Bodhidharma, an important figure in the Buddhist tradition. According to the legend, Bodhidharma, who is credited with founding the Zen school of Buddhism, traveled to China to spread Buddhist teachings. The story goes that during his meditations, Bodhidharma fell asleep. Upon waking and discovering that he had succumbed to sleep, he was so distraught that he cut off his eyelids in frustration over h
- GeneralClass 12All
What are plant hormones? Explain with examples and functions?
Plant hormones, also known as phytohormones, are chemical substances produced in plants that regulate growth, development, and other physiological processes. Unlike animal hormones, they are not produced in specialized glands but in various parts of the plant, including roots, stems, leaves, and fruits. These hormones are active in very small concentrations and can have profound effects on plant growth and development. Here are some key plant hormones with their functions and examples: <
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How to reduce pollution?
Reducing pollution is essential for the well-being of our planet and its inhabitants. Pollution can take many forms, including air pollution, water pollution, soil pollution, and noise pollution. It is often the result of human activities and industrial processes. Here are some strategies and actions to help reduce pollution: Reduce Energy Consumption: Use energy-efficient appliances and lighting. Improve home insulation to reduce heating and cooling e
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How many types of blood groups?
The ABO blood group system and the Rh factor are the two major blood group systems that classify human blood into various types. These systems determine the presence or absence of specific antigens on the surface of red blood cells. The combination of these antigens leads to different blood types. The four main blood types within the ABO system are A, B, AB, and O, while the Rh factor adds a positive or negative designation, resulting in a total of eight possible blood types:
- GeneralClass 12All
How many percent of water in the earth?
Water covers approximately 71% of the Earth's surface. This water is primarily found in the form of saltwater in the Earth's oceans and seas, which account for about 97.5% of the Earth's total water volume. The remaining 2.5% of Earth's water is freshwater, with the majority of that freshwater being stored in glaciers and ice caps (about 68.7%). The remaining freshwater is found in groundwater (30.1%), while a very small fraction is found in lakes, rivers, and in the atmosphere. To su