modern physics of 10 class

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Radio waves are electromagnetic waves of wavelength 10 - 3 m and higher. Their frequency range is from a few kHz to nearly a few hundred MHz. The propagation of radio waves through the atmosphere is relevant in all modern forms of communication: radio, television, microwaves etc..

Even though the laws of friction have been understood since a long time, some properties were understood properly, only after the discovery of atoms and molecules. No matter how well polished two surfaces are, at the atomic level they are never plane. Sometimes, when these extremely well polished ..

(c) Cathode rays get deflected in the magnetic field. Figure (c) above shows a beam of cathode rays being deflected by the magnetic field. By applying 'Flemings left hand rule' we can also prove that they are negatively charged particles. Cathode rays travel with a great velocity nearly of the spee..

Radioactive Decay or Disintegration - A radioactive nucleus or element emits an alpha or a beta particle and gets converted into a new nucleus or element. The process of destruction of the original nucleus during the formation of new nucleus due to radioactivity is called Radioactive decay or disin..

In the chapter on current electricity, we had learnt about the flow of charges, conditions to produce the flow and how different materials respond to an external electric field. We had seen how materials are classified as conductors and insulators. In this chapter, we will study a new type of mater..

The atmosphere is the layer of air around the earth. It extends up to 1000 km above the surface of the earth and has a total weight of 4.5 10 1 8 kg (i.e., five million billion tons). This weight exerts a pressure on the surface of the earth which is called atmospheric pressure . At s..

When the pressure in the discharge tube is less than 10 - 4 mm of Hg, the discharge tube starts showing fluorescence. When this fluorescence was investigated, it was found that the fluorescence consisted of beams of negatively charged electrons. These electrons emanate normally from the c..

Modern Physics..