Topics
Chemical Reactions and Equations
- Chemical Equation
- Balancing Chemical Equation
- Types of Chemical Change or Chemical Reaction
- Direct Combination (or Synthesis) Reaction
- Decomposition Reactions
- Single Displacement Reactions
- Double Displacement Reaction
- Oxidation, Reduction and Redox Reactions
- Corrosion of Metals and Its Prevention
- Rancidity of Food and Its Prevention
Chemical Substances - Nature and Behaviour (Chemistry)
Acids, Bases and Salts
- Acids
- Bases (Alkalis)
- Indicators
- Properties of Acids
- Properties of Bases (Alkalis)
- Acid or a Base in a Water Solution
- Similarities and Differences Between Acids and Bases
- Strength of Acidic or Basic Solutions
- Salts
- Important Salts in Daily Life
- Preparation and Uses of Sodium Hydroxide
- Preparation and Uses of Bleaching Powder
- Preparation and Uses of Baking Soda
- Preparation and Uses of Washing Soda
- Preparation and Uses of Plaster of Paris
World of Living (Biology)
Metals and Non Metals
- Types of Elements: Metals
- Physical Properties of Metals
- Chemical Properties of Metal
- Types of Elements: Non-metal
- Physical Properties of Non-metal
- Chemical Properties of Non-metal
- Electrovalent (or Ionic) Bond
- Reactivity Series of Metals
- Extraction of Metals
- Refining of Metals
- Corrosion of Metals and Its Prevention
- The Covalent Bond
Natural Phenomena (Physics)
Carbon and its Compounds
- Carbon: a Versatile Element
- The Covalent Bond
- Saturated and Unsaturated Carbon Compounds
- Allotropy and Allotropes of Carbon
- Crystalline Allotropes of Carbon: Diamond
- Crystalline Allotropes of Carbon: Graphite
- Crystalline Allotropes of Carbon: Fullerene
- Chains, Branches and Rings of Carbon Compound
- Functional Groups in Carbon Compounds
- Homologous Series of Carbon Compound
- Nomenclature of Organic Compounds (IUPAC)
- Chemical Properties of Carbon Compound
- Ethanol
- Ethanoic Acid
- Soap
- Detergents
- Cleansing Action of Soap
Effects of Current (Physics)
Natural Resources
Periodic Classification of Elements
- History of Periodic Table: Early Attempts at the Classification of Elements
- Dobereiner’s Triads
- Newland's Law of Octaves
- Mendeleev’s Periodic Table
- Merits and Demerits of Mendeleev’s Periodic Table
- The Modern Periodic Table
- Periodic Properties
- Periodic Properties: Valency
- Periodic Properties: Atomic Radius Or Atomic Size
- Periodic Properties: Metallic Character
- Periodic Properties: Non-metallic Character
Life Processes
- Living Organisms and Life Processes
- Nutrients and Nutrition
- Mode of Nutrition in Plant
- Autotrophic Nutrition
- Heterotrophic Nutrition
- Different Ways of Taking Food
- Human Digestive System
- The Mouth and Buccal Cavity
- The Teeth and Its Structure
- The Salivary Glands
- Swallowing and Peristalsis
- The Food Pipe/Oesophagus
- The Stomach
- The Small Intestine
- Pancreas
- Absorption of Food
- The Large Intestine
- Assimilation of Food
- Liver
- Respiration
- Respiration in Organisms
- Breathing in Other Animals
- Osmoregulation
- Types of Respiration: Aerobic and Anaerobic Respiration
- Human Respiratory System
- Circulation
- Blood
- Composition of Blood: Plasma (The Liquid Portion of Blood)
- Composition of Blood: Red Blood Cells (Erythrocytes)
- Composition of Blood: White Blood Cells (Leukocytes)
- Composition of Blood: Blood Platelets (Thrombocytes)
- Blood Circulatory System in Human
- Human Heart
- Blood Vessels – Arteries, Veins, and Capillaries
- Circulation of Blood in the Heart (Functioning of Heart)
- Types of Blood Circulation
- Heart Beat - Heart Sounds "LUBB" and "DUP"
- Function of Platelets - Clotting of Blood (Coagulation)
- Lymph and Lymphatic System
- Blood Pressure (B.P.)
- Transportation of Water and Food in Plants
- Water and Mineral Absorption by Root
- Translocation of Water (Ascent of Sap)
- Translocation of Mineral Ions
- Transport of Food
- Transpiration
- Excretion: Substances to Be Eliminated
- Human Excretory System
- Function of the Kidney - “Production of Urine”
- Excretion in Plants
Internal assessment
Control and Co-ordination
- Control and Co-ordination in Animals
- Human Nervous System
- Neuron (Or Nerve Cell) and Its Types
- Neuron as Structural and Functional Unit of Neural System
- Nerve Fibres
- Major Division of the Nervous System
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
- The Human Brain
- Central Nervous System (CNS): Structure of Human Brain
- Reflex and Reflex Action
- Nervous Pathways in Reflexes
- Reflex Arc
- Co-ordination in Plant: Tropism in Plants
- Hormones
- Plant Hormones
- Types of Plant Hormones: Auxins
- Types of Plant Hormones: Gibberellins
- Types of Plant Hormones: Ethylene
- Types of Plant Hormones: Cytokinins
- Types of Plant Hormones: Abscisic Acid (ABA)
- Types of Plant Hormones: Ethylene
- Hormones in Animals
- Human Endocrine System
- Pituitary Gland or Hypophysis Gland
- Thyroid Gland
- Parathyroid Gland
- Pancreas (Islets of Langerhans)
- Adrenal Gland (Suprarenal Gland)
- Reproductive Glands (Gonads)
- Thymus Gland
How do Organisms Reproduce?
- Accumulation of Variation During Reproduction
- Reproduction in Plant
- Mode of Reproduction in Plant
- Asexual Reproduction in Plant
- Natural Vegetative Reproduction
- Sexual Reproduction in Flowering Plants
- Sexual Reproduction in Animals
- Human Reproductive System
- The Male Reproductive System
- The Female Reproductive System
- Menstrual Cycle (Ovarian Cycle)
- Reproductive Health
- Sexually Transmitted Diseases (STD)
Heredity and Evolution
- Accumulation of Variation During Reproduction
- Heredity
- Gregor Johann Mendel – Father of Genetics
- Inheritance of One Gene (Monohybrid Cross)
- Inheritance of Two Genes (Dihybrid Cross)
- Mendelian Inheritance - Mendel’s Laws of Heredity
- Sex Determination
- Evolution
- Lamarck’s Theory of Evolution
- Darwin’s Theory of Natural Selection
- Theories of Origin of Life
- Speciation
- Evolution and Classiffication
- Evidences for Biological Evolution
- Paleobotany
- Evolution by Stages
- Origin and Evolution of Man
Light - Reflection and Refraction
- Reflection of Light
- Law of Reflection of Light
- Mirrors and Its Types
- Plane Mirror and Reflection
- Spherical Mirrors
- Rules for the Construction of Image Formed by a Spherical Mirror
- Images Formed by Spherical Mirrors
- Concave Mirror
- Image Formation by Concave Mirror
- Convex Mirror
- Image Formation by Convex Mirror
- Sign Convention for Reflection by Spherical Mirrors
- Mirror Equation/Formula
- Linear Magnification (M) Due to Spherical Mirrors
- Refraction of Light
- Refraction of Light Through a Rectangular Glass Slab
- Law of Refraction of Light
- Refractive Index
- Spherical Lens
- Images Formed by Sperical Lenses
- Guideline for Image Formation Due to Refraction Through a Convex and Concave Lens
- Concave Lens
- Images Formed Due to Refraction Through a Concave Lens
- Convex Lens
- Images Formed Due to Refraction Through a Convex Lens
- Sign Convention for Spherical Lenses
- Lens Formula
- Magnification Due to Spherical Lenses
- Power of a Lens
The Human Eye and the Colourful World
- Human Eye: Structure of the Eye
- Working of the Human Eye
- Eye Defect and Its Correction: Myopia Or Near-sightedness
- Eye Defect and its correction: Hypermetropia or far-sightedness
- Eye Defect and Its Correction: Presbyopia
- Care of the Eyes
- Refraction of Light Through a Prism
- Concept of Prism
- Dispersion of Light Through Prism and Formation of Spectrum
- Atmospheric Refraction
- Application of Atmospheric Refraction
- Scattering of Light and Its Types
- Applications of Scattering of Light
Electricity
- Electricity
- Electric Current
- Electric Circuit
- Potential and Potential Difference
- Symbols and Functions of Various Components of an Electric Circuits
- Ohm's Law
- Factors Affecting the Resistance of a Conductor
- Electrical Resistivity and Electrical Conductivity
- Resistors in Series
- Resistances in Parallel
- Effects of Electric Current
- Heating Effect of Electric Current
- Electrical Power
Magnetic Effects of Electric Current
- Magnetic Effect of Electric Current
- Magnetic Field
- Magnetic Field Lines
- Magnetic Field Due to a Current Carrying Straight Conductor
- Rule to Find the Direction of Magnetic Field
- Magnetic Field Due to Current in a Loop (Or Circular Coil)
- Magnetic Field Due to a Current Carving Cylindrical Coil (or Solenoid)
- Force on a Current Carrying Conductor in a Magnetic Field
- Electric Motor
- Electromagnetic Induction
- Faraday's Laws of Electromagnetic Induction
- Electric Generator
- Alternating Current (A.C.) Generator
- Direct Current Motor
- Household Electrical Circuits
- Distinction Between an A.C. Generator and D.C. Motor
- Types of current: Alternating Current (A.C.) and Direct Current (D.C.)
Sources of Energy
- Source of Energy
- Conventional Sources of Energy and Non-conventional Sources of Energy
- Fossil Fuels
- Heat Energy (Thermal Energy)
- Hydroelectric Energy
- Bio-energy
- Wind Energy
- Solar Energy
- Solar Energy Devices
- Energy from the Sea
- Geothermal Energy
- Nuclear Energy
- Nuclear Fission
- Different Forms of Energy
- Environmental Consequences
- How Long Will an Energy Source Last Us?
Our Environment
Sustainable Management of Natural Resources
- Sustainability of Natural Resources
- Case Study: Ganga Pollution and Ganga Action Plan
- Solid Waste Management
- Five R’s of Waste Management
- Conservation and Judicious Use of Resources
- Forests: Our Lifeline
- Stakeholders of Forest
- Conservation of Forest
- Conservation of Wildlife
- Water Management (Conservation of Water)
- Fresh Water Management
- Non-crystalline/Amorphous Forms: Coal
- Petroleum
- Conservation of Coal, Petroleum, and Natural Resources
- Overview of Natural Resource Management
notes
ELECTRIC MOTOR:-
-An electric motor is a rotating device that converts electrical energy to mechanical energy. Electric motor is used as an important component in electric fans, refrigerators, mixers, washing machines, computers, MP3 players etc.
-An electric motor consists of a rectangular coil ABCD of insulated copper wire. The coil is placed between the two poles of a magnetic field such that the arm AB and CD are perpendicular to the direction of the magnetic field
-The ends of the coil are connected to the two halves P and Q of a split ring. The inner sides of these halves are insulated and attached to an axle. The external conducting edges of P and Q touch two conducting stationary brushes X and Y, respectively
-Current in the coil ABCD enters from the source battery through conducting brush X and flows back to the battery through brush Y. Notice that the current in arm AB of the coil flows from A to B. In arm CD it flows from C to D, that is, opposite to the direction of current through arm AB.
-On applying Fleming’s left hand rule for the direction of force on a current-carrying conductor in a magnetic field
-We find that the force acting on arm AB pushes it downwards while the force acting on arm CD pushes it upwards. Thus the coil and the axle O, mounted free to turn about an axis, rotate anti-clockwise. At half rotation, Q makes contact with the brush X and P with brush Y. Therefore the current in the coil gets reversed and flows along the path DCBA
-A device that reverses the direction of flow of current through a circuit is called a commutator. In electric motors, the split ring acts as a commutator. The reversal of current also reverses the direction of force acting on the two arms AB and CD.
-Thus the arm AB of the coil that was earlier pushed down is now pushed up and the arm CD previously pushed up is now pushed down. Therefore the coil and the axle rotate half a turn more in the same direction. The reversing of the current is repeated at each half rotation, giving rise to a continuous rotation of the coil and to the axle.
-The commercial motors use
(i) an electromagnet in place of permanent magnet
(ii) large number of turns of the conducting wire in the current carrying coil
(iii) a soft iron core on which the coil is wound. The soft iron core, on which the coil is wound, plus the coils, is called an armature. This enhances the power of the motor.
