“The Knowledge Library”

Knowledge for All, without Barriers…

An Initiative by: Kausik Chakraborty.
04/02/2023 1:28 PM

“The Knowledge Library”

Knowledge for All, without Barriers……….
An Initiative by: Kausik Chakraborty.

The Knowledge Library

General Science

STARS

Introduction The moon completes one rotation around its axis in 29 days and the same time it takes to complete one revolution around the earth.

Read More »

SURFACE TENSION

Introduction Surface tension explains why Bubbles are spherical. Water doesn’t spread on some surfaces but forms droplets. Oil and water don’t mix; water wets us

Read More »

METHODS OF SEPARATION

  Introduction Threshing: Beating stalks to free grains Winnowing: Separate lighter and heavier components of a mixture by blowing air. Sieving: Separate components of different

Read More »

SOUND

Introduction What is Sound? Sound is produced by vibrating objects. Vibrations cause compressions [high pressure] and rarefactions [low pressure]. Sound waves travel through a medium

Read More »

FORCE

Introduction This is either contact [friction, muscular] or non-contact [magnetic, electrostatic, gravitational, pressure] Pressure Pressure is inversely related to the area. So smaller the area,

Read More »

HEAT

Introduction When a solid is heated the kinetic energy of the molecules is increased and it overcomes the force of attraction of molecules and the

Read More »

ELECTRICITY AND CIRCUITS

Conductors and Insulators Conductors –allow electricity to pass through them. Due to free electrons present on their surface. [Metals, Human body] Insulators – Don’t allow electricity to

Read More »

CLIMATE

Climate Air moves from a region of high air pressure to low air pressure. Air when heated rises as it becomes lighter. Air expands on

Read More »

HORMONES

  Human Hormones     The pituitary gland is an endocrine [ductless] gland. The hormones of the pituitary gland stimulate testes and ovaries to produce their

Read More »

CHROMOSOMES

Introduction The male has two chromosomes X and Y, the female has only X chromosomes. During reproduction, if the X and X chromosomes come together then

Read More »

ORGANISMS AND ENVIRONMENT

Introduction Ecology – the study of the relationship between organisms and the environment Ecosystems – functional unit of nature encompassing interaction between its biotic and abiotic components.

Read More »

BODY JOINTS

  Introduction Ball and Socket joint – The rounded end of one bone fits into the cavity of the other bone. Such a joint allows movement

Read More »

SOIL

  Introduction Soil has the following layers: Topsoil or A-Horizon: Humus, the topmost layer, retains water, and provides shelter to organisms B-Horizon: Middle layer, harder and

Read More »

ENVIRONMENT

  Introduction Herbs – Plants with green and tender stems and almost no branches. E.g: Tomato – Herb Shrubs – Branches near the base, thin but hard

Read More »

WATER

  Introduction 22 March is World water day. UN recommends 50 liters of water per person per day. 2003 was the international year of freshwater

Read More »

MIXTURES

Introduction Homogenous mixtures have a uniform composition throughout e.g. salt water and sugar water, tincture alcohol [iodine+alcohol]. Solid solutions like alloys [brass = zinc + copper]

Read More »

ELEMENTS

  Introduction Metals are malleable [can be beaten into sheets], ductile [pulled into wires] and conductors of heat and electricity, and sonorous [produce ringing sounds when

Read More »

FABRICS

  Introduction    Fabrics like cotton, silk are made of yarns and yarns are made of fibers. Types of Fibers: Natural Fibers: Cotton, jute [plant], silk [cocoon of

Read More »

CELLS

  Introduction    Bodies of organisms are made of tiny units called Cells. Cells have an outer boundary called a cell membrane [made up of lipids

Read More »

MICRO-ORGANISMS

  Introduction Microorganisms are of four types: bacteria [TB, typhoid, cholera, diphtheria, and plague], algae, protozoa [dysentery, malaria], and fungi. Virus [jaundice] reproduces only inside

Read More »

Blood and Constituents

  Introduction     Blood contains a fluid part called plasma. Red blood cells [erythrocytes] have red pigment hemoglobin which binds oxygen and transports it to all cells.

Read More »

NUTRITION

Introduction Components of food necessary for the body are called Nutrients. Organisms that prepare food themselves from simple substances are called Autotrophs and animals that take in ready-made

Read More »