Integers Properties of integers For a, b ϵ I, we have: a + b ϵ I a – b ϵ I a × b ϵ I If a, b ϵ I, then a + b = b + a a × b = b × a If a, b, c ϵ I, then a + […]
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Light Light Reflection of Light Laws of Reflection The laws of reflection are: Types of Reflection Regular Reflection Irregular Reflection or Diffused Reflection Left-Right Inversed Characteristics of an Image Spherical Mirrors Concave Mirror Uses of Concave Mirrors Convex Mirror Uses of Convex Mirrors Types of Images formed by a Mirror Virtual Image Real Image Example:
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Electric Current and its Effects Electric Current The flow of charges through a circuit is called electric current. The SI unit of electric current is ampere and donated by A. The direction of the electric current is conventionally from the positive terminal to the negative terminal of a cell. Electric Current and Its Effects: Electrical
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Motion and Time Motion Examples: Chairs of a dining table, a flower vase, table, blackboard etc. Examples: The blades of a rotating fan, the hands of a working wall clock etc. Slow and Fast Motion Rectilinear Motion Circular Motion Rotational Motion Periodic Motion Speed Average Speed Average speed Total distance covered Total time taken Measurement
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Heat Concept of Heat Temperature Thermometer Clinical Thermometer Laboratory Thermometer Maximum-Minimum Thermometer Scales of Temperaturesss Transfer of Heat Conduction Convection Radiation Examples: SUMMER AND WINTER CLOTHING: Important Questions Question 1. Which of the following is a good conductor of heat? (a) Iron (b) Steel (c) Aluminium (d) All of these Question 2. A device used
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Physical and Chemical Changes There are two types of changes, physical and chemical changes. Physical Changes Example: Melting of ice and freezing of water. Examples of physical change: Definition of Chemical Change Chemical change is a permanent change which cannot be reversed and in which the chemical properties of a substance change with the change
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Acids, Bases and Salts Chemicals can be broadly classified into three categories, acids, bases and salts. Acids Examples: Hydrochloric acid and sulphuric acid are corrosive acids. Carbonic acid is a non-corrosive acid. Organic acids: Naturally occurring acids obtained from plants and animals. Mineral acids: They are obtained from minerals present in the Earth’s crust. Bases
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Wastewater Story Water – Our Lifeline Sewage Types of Impurities Examples Organic impurities Human faeces, animal wastes, oil, urea, pesticides,herbicides, fruit and vegetable wastes Inorganic impurities Nitrates, phosphates, metals Nutrients Phosphorus and nitrogen Bacteria Those which cause diseases such as cholera, dysentery andtyphoid Sources of wastewater: Treatment of sewage in cities and towns: If sewage
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Reproduction in Plants Asexual Reproduction Vegetative Propagation (a) Vegetative Propagation by Stems The stems (or branches) of plants normally bear buds in the axils which can be used in vegetative propagation to produce new plants. New plants can be obtained from the stem (or branch) of an existing plant by the method of cuttings. A
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Transportation in Animals and Plants Circulatory System Blood plasma. Blood Vessels Heart The arteries and veins in the heart connect to other parts of the body. The blood vessels that enter or leave the heart are: Vena cava: It is a large vein that collect blood rich in carbon dioxide from all parts of the
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