General Science and Technoloy

Electromagnetic Wave Electromagnetic Wave are waves composed of undulating electrical fields and magnetic fields. The different kinds of electromagnetic waves, such as light and radio waves, form the electromagnetic spectrum. All electromagnetic waves have the same speed in a vacuum, a speed expressed by the letter c (the speed of light) and equal to about … Read more Electromagnetic Waves

Semiconductor Devices:- Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide, as well as organic semiconductors. Semiconductor devices have replaced thermionic devices (vacuum tubes) in most applications. There are two basic groups or classifications that can be used to define the different semiconductor types: Intrinsic … Read more semi conductor devices

Nuclear physics Atoms in nature generally are electrically neutral, as they have equal numbers of protons in the nucleus and orbiting electrons. However, within the nucleus there are other particles called neutrons, which are electrically neutral but have about the same mass as protons. There are two numbers used to characterize a nucleus: Z, the … Read more Nuclear physics

The photoelectric effect The photoelectric effect is the emission, or ejection, of electrons from the surface of, generally, a metal in response to incident light.A material that can exhibit The photoelectric effect is said to be photoemissive, and the ejected electrons are called photoelectrons. The process was discovered by Heinrich Hertz in 1887. Attempts to … Read more Photo electric effect

Ray Optics The wave model of light has one serious drawback, though: Unlike other wave phenomena such as sound, or surface waves, it wasn‟t clear what the medium was that supported light waves. Giving it a name – the “luminiferous aether” – didn‟t help. James Clerk Maxwell‟s (1831 – 1879) theory of electromagnetism, however, showed … Read more Ray optics

Moving Charge and Magnetism Magnetism is a phenomenon produced by the motion of electric charge, which results in attractive and repulsive forces between objects. A magnet is any piece of material that has the property of attracting iron (or steel). Magnetite, also known as lodestone, is a naturally occurring rock that is a magnet. This … Read more moving charge and magnetism

Current Electricity Electric current is the rate of flow of electric charge through a conducting medium with respect to time. It is caused by drift of free electrons through a conductor to a particular direction.Charges in motion constitute an electric current. Such currents occur naturally in many situations. Lightning is one such phenomenon in which … Read more current electricity

Electrostatic The basic principle of electrostatics is based on the fact the electric charges attract or repel other charges depending on their relative signs and the law of force is given by Coulomb‘s law. Coulomb’s law states that: The magnitude of the electrostatic force of interaction between two point charges is directly proportional to the … Read more Electrostatics

Properties of matter Matter is anything that has mass and takes up space. At a minimum, matter requires at least one subatomic particle, although most matter consists of atoms. The two properties of matter are: • Mass – amount or quantity of matter • Volume – amount of space occupiedphysical properties – inherent characteristics of … Read more Properties of matter

Waves A wave can be described as a disturbance that travels through a medium from one location to another location.It is a disturbance or variation that transfers energy progressively from point to point. It may take the form of an elastic deformation, a variation of pressure, electric or magnetic intensity, electric potential, or temperature. When … Read more waves