SCIENCE - DEFINITIONS (Std. 10th)

 

One Ampere – The flow of one coulomb charge through the cross section of the conductor in one second.

One Volt – One Volt is the potential difference across the ends of the conductor when one joule of work done to move 1 coulomb of charges

One Ohm – The Resistance of the conductor is one Ohm when the potential difference across the ends of the conductor is one Volt and the current flowing through it is one Ampere.

 Focal Length – This is the distance between the Optic center and the Principal Focus.

 Radius Of Curvature – This is the radius of the sphere of which the lens is part.

 Optic Centre – Optic Center is the geometric centre of the lens.

 Virtual Image – The Image which can’t be caught on the screen are virtual images.

 Resistivity of Conductor  - This is the electrical resistance of a conductor of unit cross-sectional area and unit length.

 Tyndall Effect – The scattering of light by the particle of the solution is called Tyndall Effect.

Refraction – The bending of the light ray when it passes from one transparent medium to another medium of different density is termed as ‘Refraction’.

 Refractive Index – The constant ratio of sine of angle of incidence to the sine of angle of refraction for a given pair of medium is called as Refractive Index.

 Electromagnetic Induction – The process by which a changing magnetic field in a conductor induces a current in another conductor is called “Electromagnetic Induction”

Electromagnet – Electromagnets are temporary magnets which are accompanied by electricity.

Amphoteric Oxides – Some of the metal oxides are Acidic as well as basic in nature. They react with both, acids as well as bases to produce salt and water.

 Galvanization – This is the method of coating zinc over other metals like iron to prevent it from rusting.

 Chlor-Alkali Process – Aqueous solution of sodium chloride decomposes when electric current is passed through it. This process is called chlor-alkali. This is because the products formed are chlorine(chlor) and sodium hydroxide(alkali)

 pH Value – Scale used to measure hydrogen ion concentration in the solution.

 Isomerism - Compounds with identical molecular formula but different structural formula are called ‘Isomers’. This property is called as Isomerism

 Roasting – Roasting is the process of strong heating sulphides ores in the presence of excess air.

 Calcination – Calcination is the process of strong heating of carbonate ores in limited supply of air.

Alloy – This is the homogeneous mixture of two or more metals or a metal and a non-metal.

 Catenation – The property of the carbon to form bonds with other carbon atoms forming a large molecule is called “Catenation”.

 Hormones – Hormones are minute, chemical messengers thrown into blood to act on target organs. Hormones can be steroids, proteins, peptides or amino acid derivatives.

 Evolution – A slow and gradual process of change and development of  something is called as Evolution

 Heredity - The process by which physical and mental qualities are passed from parents to offspring.

 Double Circulation – In vertebrates the blood goes through the heart twice during each cycle. 

Reflex Action – It is the sudden action in response to something in the environment.

 Analogous Organs – Organisms having different basic structure but perform a similar function. Eg. wings of birds and wings of  bats

 Homologous Organs – Organism have similar basic structure but perform different functions. Eg. limbs of mammals, reptiles, birds etc.

 Self-Pollination – Transfer of pollen grains from anther to the stigma of the same flower or the flower of the same plant is called self pollination

 Cross Pollination – Transfer of pollen grains from the stamen to stigma to another flower of another plant is called cross pollination

 Fossils – When organism die other bodies may be decomposed but sometimes the body or some parts of the body does not decompose completely and an impression the same may be found in mud. All such preserved traces of living organisms are called Fossils.

Bio magnification – Increase in concentration of toxic substance from one tropic level to another.

 Dominant Trait – The traits that are shown up in the organisms are called as Dominant traits

 Phototropism - Growth of the plant towards the light is Phototropism.

 Speciation – The formation of new and distinct species in the course of evolution.

 Endocrine glands - Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones, directly into the blood.

 Transpiration - The loss of water molecules in the form of vapour from the aerial parts is known as ‘Transpiration’.