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 Refraction of light Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another.  This bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Even our eyes depend upon this bending of light. … Read more

 Electric discharge in gases Electrical discharge through gases is studied by using a specially designed glass tube commonly called as a discharge tube. It consists of a cylindrical glass tube having a side tube, and two metallic electrodes one at each end. These electrodes can be connected to the respective terminals of a … Read more

 Vaccines Subscribe on YouTube A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins. The agent stimulates the body’s … Read more

 Excretion:In plants Excretion, the process by which animals and plants rid themselves of waste products and of the nitrogenous by-products of metabolism. Through excretion organisms control osmotic pressure—the balance between inorganic ions and water—and maintain acid-base balance. The process thus promotes homeostasis, the constancy of the organism’s internal environment. Plants have no special … Read more