CBSE ADDA

CBSE ADDA Temperature, Heat, and the Particle Theory           1.         What is a theory and can they be changed? A theory is an explanation based on all the available information.  A theory can be changed when new evidence is discovered. The Particle Theory 2.         According to the Particle Theory, what four characteristics are common to all matter? According to the Particle Theory: 1.  All matter is made up of tiny particle too small to see. 2.  These tiny particles are always moving 3.  The tiny particles have energy 4.  The more energy the particles have the faster they move 3.         Use the Particle Theory of Matter to explain why pollen grains move around when placed in a glass of water. Pollen grains move around in a glass of water because they are being pushed around by the invisible particles in water. Heat and Temperature 4.         Using the particle theory, explain Heat and Temperature. The invisible particles in matter move because they have energy.  Th

CBSE ADDA We have all noticed that when you heat something up, its temperature rises. Often we think that heat and temperature are the same thing. However, this is not the case. Heat and temperature are related to each other, but are different concepts. Heat is the total energy of molecular motion in a substance while temperature is a measure of the average energy of molecular motion in a substance. Heat energy depends on the speed of the particles, the number of particles (the size or mass), and the type of particles in an object. Temperature does not depend on the size or type of object. For example, the temperature of a small cup of water might be the same as the temperature of a large tub of water, but the tub of water has more heat because it has more water and thus more total thermal energy It is heat that will increase or decrease the temperature. If we add heat, the temperature will become higher. If we remove heat the temperature will become lower. Higher temperatures

CBSE ADDA Current Electricity The term ‘current’ in general stands for the continuous flow of any material particles, e.g. water current means continuous flow of water particles through a pipe or a channel. Electric current in general means a continuous flow of electrons, ions or any electrically charged particles through a medium. In our everyday life, we are familiar with the electric current flowing through metallic conductors where flow of electrons only takes place. Positive charges can flow only through gases and nonmetallic solids and liquids. Units of electrical quantities I. Charge: The unit of charge in the S.I. system is coulomb. 2. Current strength: Current strength is often simply called current, its symbol is ‘I’ and the SI unit of it is ampere. Idea of resistance-its influence on regulating current The term "resist" means to oppose, so the property of opposing or resisting flow of electric charges in a conductor means resistance. The body resisting flow of ch

CBSE ADDA Work, Power, Energy & Simple Machines Definition of work Work is said to be done if due to application of an external force on a body there is actual displacement of the body, except when the displacement is perpendicular to the direction of force. Work = Force x displacement of the point of application (body on which force is applied) in the direction of force. If W = work done, F = applied force, d = displacement of the point of application in the direction of force, then from the definition of work, W = F x d. Units of work In C.G.S. the unit of work is Erg. In M.K.S. it is Joule. 1 Joule = 107 Erg. Work done by a force If the point of application moves in the direction of applied force, work is done by the force. Work done against a force If a body has its displacement in the opposite direction of the applied force, work is done against the force. Power Rate of work done by an agent is known as its power. If w work is done by a body or a system in time t, then the p