Shailesh Koirala 
S.N Name of alloys Composition of the alloy 1. Brass Cu + Zn – used for condenser, cartridge, etc. 2. Bronze Cu + Sn (20%) – used for machine parts, utensils, coins, etc. 3. German silver Cu + Zn + Ni – used for planes, ornaments, etc. 4. Rolled gold Cu +Al 5. Bell metal … Read more
S.N Mass Weight 1. The amount of matter contained in a body is called mass. The force by which earth attracts or pull objects towards its center is called weight. 2. It remains always constant regardless of the location in universe. It varies from place to place. 3. It is measured by ordinary or beam … Read more
S.N Electrovalent compounds Covalent compounds 1. These compounds are formed by transfer of electrons between atoms. These compounds are formed by mutual sharing of electron pairs between atoms. 2. Can conduct electricity in molten or solution state. Cannot conduct electricity. 3. Have high melting and boiling point. Have low melting and boiling point. 4. They … Read more
There are various species of biotic community living together in the same environment. They interact with each other for various things like food, shelter and habits. They show positive as well as negative interactions. Some of them are as follows: A) Positive interactions … Read more
S.N Soaps Detergents 1. These are sodium salts of long chain fatty acids. These are sodium salts of a long chain of benzene sulphonic acid. 2. These are prepared from plants or animals fats. These are prepared from hydrocarbon of petroleum. 3. Relatively weak cleansing action. Relatively strong cleansing action. 4. Not suitable for washing … Read more
Tetra-four, podos-feet Primarily terrestrial, some are secondarily aquatic. Two pairs of pentadactyl limbs. Body covered by an exoskeleton of epidermal hair, feathers or scales. Lungs are main respiratory organs. Amphibian may respire by gills, skin or lungs. 3 or 4 chambered heart present. They are divided into 4 classes: Class 2: Amphibia Amphi-dual; bios-life. Dual … Read more
S.N Plant cell Animal cell 1. It is surrounded by a distinct cell wall made up of cellulose. It is surrounded by cell membrane or plasma membrane. Cell wall is absent. 2. Chlorophyll is present. Chlorophyll is absent. 3. Plastids are present. Plastids are absent. 4. Autotrophic in nutrition. Heterotrophic in nutrition. 5. Shows continuous … Read more
1. Apiculture The rearing of bees especially for commercial purposes. 2. Agronomy Branch of agricultural science which deals with the study of crops and soils. 3. Forestry The science or practice of planting, caring, and managing forests. 4. Agriculture The science of practice of cultivating the land and improving the crops. 5. Horticulture Practice of … Read more
S.N Apes Man 1. They have small brain box ranging from 395 cc (Orangutan); 400 cc (Chimpanzee) to 520 cc (Gorilla). Man has a large brain box 1200-1400 cc. 2. Occipital condyles posterior. Occipital condyles anterior. 3 Have a semi erect posture. Has a fully erect posture. 4. The backbone forms a simple curving arch. … Read more
1. Morphology Study of external form and structure of living organisms. 2. Anatomy Study of internal structure of plants and animals. 3. Histology Study of details of tissue structure of organisms. 4. Cell biology Study of structure, functions, reproduction and life history of cell. 5. Molecular biology Study of physio-chemical organization of biomolecules. 6. Physiology … Read more