Definition: Alloys are the homogeneous mixture of two or more metals( non metals). Why are alloys made : to improve the properties of substance. Common alloys :1 Stainless steel Composition: Iron +Chromium + Carbon + Nickel &nb . . .
Definition- Anything that occupies space has mass is called matter. Volume- The space occupied by any substance is called volume. Mass-The amount of matter contained in a body is called its mass. States of matter – Matter exist in three states. Solid, Liquid and gas. Interconversion of state- The change . . .
Shearing : The process of removing woolen coat (fleece) from the animal is called Shearing. Scouring : It involves washing of wool in hot water and detergent and then drying. Sorting : The process of removing damaged and inferior wool is called Sorting. Grading : The process of sorting wool according to length colour and texture is called Gradi . . .
Silk and Wool are most commonly used animal fibre.Silk is obtained by silk worm. Wool fibres are obtained from sheep, goat, angora rabbits and camels. Common breeds or Indian sheep are Lohi, Nali, Bakharwal and Marwari. The Merino sheep is widely reared for wool. The Cashmere goats are found in mountain region of china and Tibet a . . .
Definition: Scattering of seeds away from their parent plant is known as dispersal of seeds. It is very important to scatter the seed because each new plant need enough food, water, sunlight and space to grow. Agents of seed dispersal Wind : Some seed are very light and have hair or wings. They a . . .
Definition : Simple machines are tools which makes our work easier and faster Examples of simple machines are- Lever it is a rod or bar supported by fulcrum and effort. It reduces the the force by a push or a pull. Pulley is a small wheel with grooves around its outer edge. A pulley together with a chain or a rope is used to lift . . .
METHODS OF SEPARATION The process by which mixtures are separated to get pure substances is called separation A. Separation of solid-solid mixture 1 Hand picking- This method is used when quantity of mixture is small and substance which has to be separated I in the small portion. Ex. Small stones from grains. 2. Winnowing- This met . . .
Ploughing The loosening of soil for sowing of seed is called ploughing. It makes the soil to pass the air. Sowing Scattering of seeds into the soil is called sowing. Adding fertilizers Seeds require nutrients for proper growth. These nutrients increase fertility of soil and are called fertilizers. Irrigation Watering of plants is ca . . .
The hot and strong which blow during summer season is called heat stroke. When a person suffered from heat stroke he/she feels tired, giddy, headache and burning sensation while urination. In case of heat stroke, a person should immediately move to a cool place. A glass of lemonade helps to cool the body. Heat stroke may also lead to bleedin . . .
The atmosphere extends up to 1000km. above the earth. It is divided into five layers. 1. Troposphere: this is the inner most layer of atmosphere and is nearest to the ground. It extends up to 7km. to 17 km. above the earth. Most of the weather changes takes places here. Clouds, rain and smoke are formed in this layer. Living things can breathe comfor . . .
Q. Why is the cell called the structural and functional unit of life? Ans. Each living cell has the capacity to perform certain basic functions that are characteristic of all living forms. Each cell has some specific components in it known as cell organelles. Each cell acquires its structure and ability to function because of the organisation of its . . .
Animal cannot prepare their own food. They directly or indirectly depend on plant for their food. Different animals eat different kind of food. Some animals eat grass and plants only. Some animals eat flesh from other animals. Some animals eat both, plant and animals. On the basis of the food they eat, animals are classified as follows: . . .
According to law of conservation of energy total energy of the universe is conserved. The energy cannot be created nor be destroyed. It can simply be converted from one form to another. Let us consider the following examples in which one form of energy converts to another. A cell or battery converts chemical energy into electric energy. A mic . . .
All sources of energy divided into two groups: Conventional sources of energy. Non- Conventional sources of energy. The fuel like wood, coal and petroleum are major conventional sources of energy. Wood and coal convert chemical energy into heat energy. Petroleum converts chemical energy into mechanical energy to run automobiles. The so . . .