Economics, or political economy, may be defined, briefly, as the study of men earning a living; or, more fully, as the study of the material world and of the activities and mutual relations of men, so far as all these are the objective conditions to gratifying desires. To define, means to mark off the limits … Read more
Optical fibers are not only used for light communication but it is used in medicine for lighting difficult place of the human body, as for example, internal organ of a man. As a result of application of optical fiber gives clear image of disturbing point. For example doctor gets possibility to check up wall of … Read more
At the interface of two media, the incident light beam is separated into two: reflected and refracted. If light falls with the angle on the surface of the interface, which differs from straight then at the interface light changes its direction. It is called refraction of light. Of the two media in which light propagated … Read more
In the Figure Illustrates the terms that we use in the study of reflected light. Represents the surface of a plane. AO, called the incident ray, is the direction in which light falls onto the reflecting surface. O is the point of incidence and OR the, reflected ray. The angles, which the incident and reflected … Read more
The idea that light travels in straight lines is uppermost, while its wave character and other physical aspects are disregarded. Since the laws of reflection and refraction corollaries of the wave nature. Sources of light, such as the sun, stars, and electric lamps can be seen when the light they produce reaches the eyes. However, … Read more
What is Radioactivity? Radioactivity is the process of spontaneous disintegration of certain (unstable) atomic nuclei accompanied by the emission. Radiation is emitted by the unstable and exciting nuclei that can normally cause ionization in a matter through which they pass. These radiations can cause extensive. damage to the molecular structure of a substance either as … Read more
Transmission of Heat Heats are transferred from one region to another in three ways. They are conduction, convection, and radiation. ♦ Conduction When one end of a metal rod is heated, the unheated end soon becomes warm. This is because heat travels through the metal by the process of conduction. All electrons are constantly vibrating … Read more
Learning Objectives On completion of this lesson, you will be able to learn- ♦ x-rays ♦ properties of X-rays ♦ uses of X-rays ♦ bad effects of X-rays. Historical Background of X-rays In 1895, W.K. Rontgen a physicist at the University of Wurzburg in Germany was studied cathode rays in his laboratory. He was using … Read more