Science Tech

 Diseases of plants caused by bacteria Aster yellows Aster yellows,caused by a phytoplasma bacterium, affecting over 300 species of herbaceous broad-leafed plants. Aster yellows is found over much of the world wherever air temperatures do not persist much above 32 °C (90 °F). As its name implies, members of the family Asteraceae are … Read more

 Photosynthesis Photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds. It would be impossible to overestimate the importance of photosynthesis in … Read more

 General studies of alternating current and direct current Alternating Current Alternating Current (AC) Alternating current describes the flow of charge that changes direction periodically. As a result, the voltage level also reverses along with the current. AC is used to deliver power to houses, office buildings, etc. AC can be produced using a … Read more

 Concept of pressure Pressure is the perpendicular force per unit area, or the stress at a point within a confined fluid. The pressure exerted on a floor by a 42-pound box the bottom of which has an area of 84 square inches is equal to the force divided by the area over which … Read more

 Diseases related to heart There are many types of heart disease that affect different parts of the organ and occur in different ways. Congenital heart disease   This is a general term for some deformities of the heart that have been present since birth. Examples include:   Septal defects: There is a hole … Read more

 Linear motion Linear motion, also called uniform motion or rectilinear motion, motion in one spatial dimension.  According to Newton’s first law (also known as the principle of inertia), a body with no net force acting on it will either remain at rest or continue to move with uniform speed in a straight line, … Read more

 Matter in our surroundings, Elements, Compounds, Mixtures Matter is any thing which has mass and occupies space. All solids, liquids and gases around us are made of matter. Scientist believe that matter is made of tiny particles that clump together. You cannot see these particles but you can see the matter, for example, … Read more

 Intoxicants The intoxicants used in society  might be taken as the following: alcohol, bhang, ganja, tobacco and opium, coca etc. Alcohol as an intoxicant Alcohol, also known by its chemical name ethanol, is a psychoactive substance that is the active ingredient in drinks such as beer, wine, and distilled spirits (hard liquor). It … Read more

 Determination of focal length of concave miror by single pin method. [Relation between u-v-f (numerical examples) Spherical mirrors It is a mirror which has the shape of a piece cut out of a spherical surface. Two types of spherical mirrors are;   Concave mirror: Its inner concave surface reflects, and has polished outer … Read more

 Working principle and use of generator   Generator is a machine that converts mechanical energy into electrical energy. It works based on principle of faraday law of electromagnetic induction. The faradays law states that whenever a conductor is placed in a varying magnetic field, EMF is induced and this induced EMF is equal … Read more