NCERT Solutions for Class 9 Science Chapter 12 Sound

Price and Cost: The term“price” is the process of fixing the manufacturer’s value in exchanging services and goods. Cost is the cost of producing a product or...

Gait of Animals: All living organisms move from one place to another place in search of food, shelter, and to protect themselves from their enemies....

Ellingham Diagrams: Based on enthalpy and entropy values, the Gibbs equation allows us to predict the spontaneity of a process. H.G.T Ellingham proposed the Ellingham diagram to...

Trigonometry Formulas: Trigonometry is the branch of Mathematics. It deals with the relationship between a triangle's sides and angles. The students can learn basic trigonometry...

Properties of Whole Numbers: We begin to count the numbers as \(1,2,3,4, \ldots \). They come naturally when we start counting. Hence, mathematicians call them...

Hormones: As a child is born, he or she experiences a rapid change in the body related to growth and development. A child grows to...

Intermolecular Forces and Thermal Energy: Intermolecular forces are the forces of attraction that exist between the molecules of a substance (gaseous, liquid, or solid). These...

Buffer Solutions: A steady \({\rm{pH}}\) is required for the proper functioning of many chemical and biological systems, including our blood, for reactions to take place....

Ideal Gas: Chemists worldwide dreamt of having an equation describing a gas molecule's relation to its environmental parameters such as temperature or pressure. However, they...

Applications of Thermodynamics: In everyday conversation, when individuals talk about work, they usually mean putting effort into something. We might "work on a school project"...

Close Packed Structures and Packing Efficiency: We all know that all substances in the universe are made up of atoms. Each atom is considered a...

Reactions in Solutions: A solution is a homogeneous substance consisting of a solute and a solvent. Mostly, water act as a universal solvent and forms...

Phytochrome: Light plays a vital role in photosynthesis. Similarly, it is also very essential for plant growth and development. Light controls multiple developmental processes in...

Periodic Classification of Elements: You must have noticed in a retail shop, to make it easier to find related items, the shopkeeper arranges them together...

Principle of Calorimetry: When we talk about energy, we generally talk about the kinetic energy and potential energy of an object as a whole. Kinetic...

Experiment Based on Hard and Soft Water: As we know, a major part of living organisms is made up of water. With water being very...

Measurement of Energy Changes - Calorimetry: We all know the fact that energy can neither be created nor be destroyed. Every substance in this universe...

Forced Oscillations and Resonance: Would you believe if you were told that a group of soldiers once broke a bridge just by marching over it?...

Proteomics, Biochip and Forensic Technologies: In the post-genomic era, proteomics is a new field of study that involves determining the structures and functions of all...

Activation Energy Formula: In our body, millions of chemical reactions take place every time. These chemical reactions are responsible for supporting life. Now, many molecules...

Combustion and Respiration: Combustion is the process of burning something. Any carbon-containing substance reacts with oxygen to produce carbon dioxide gas, water vapour, along with...

Properties of Real Number: Real numbers are any numbers one can think of. In other words, real numbers are all the numbers that are rational...

Geothermal Energy: Countries worldwide are much more aware of the damages that the rampant use of fossil fuel-based sources of energy are causing. Therefore, there...

Ratio: Comparison is a general phenomenon used in daily life to compare two similar quantities. It is used to compare how big or small one...

Kinetic Molecular Theory of Gas: We have learned about different laws applied to ideal gases. Like any laws, these ideal gas laws are merely summaries...

Flagella and Cilia: Have you seen some microorganisms like Euglena and Paramoecium having hair-like or thread-like appendages that help the movement? The Flagella and Cilia are microscopic, contractile and filamentous processes...

Relationship between Zeroes and Coefficients of a Polynomial: Polynomials are algebraic expressions made up of variables and constants that have whole number exponents. We know...