modern physics class

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Introduction - You have learnt in the earlier chapters that flow of electrons constitutes an electric current and current can be generated from a battery or a generator. Scientists later discovered that there are many other ways of producing the stream of electron..

Summary - When certain metals are heated to a high temperature, they emit thermions (electrons) and the phenomenon is called thermionic emission Cathode rays are a stream of negatively charged particles emitted from the cathode of an evacuated bulb, when a voltage of nearly 3000 volts given across ..

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. The earl..

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 ..

Cathode rays travel in straight lines from the cathode to anode and cast shadow of the object placed in their path. (a) Cathode rays travel in straight lines. Cathode rays consist of an invisible stream of negatively charged particles. When the plates X and Y are given +ve and -ve potent..

Mathematics has served as a powerful tool in the development of modern theoretical physics..

The phenomenon of spontaneous disintegration of an unstable nucleus of naturally occurring isotope accompanied by emission of active radiations line a , b and g radiations is known as Natural Radioactivity. These radiations come from the breakup of the central core or nuclei of heavier elemen..

Introduction - Humans have always been curious about the world around them. The world has an astonishing variety of materials and bewildering diversity of life and behaviour. The inquiring and imaginative human mind has responded to the wonder and awe of nature in different ways. This human endeavo..