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Need for Modulation - The velocity of electromagnetic waves is 3 x 10 8 ms - 1 . On the other hand, the velocity of sound waves cannot be used to transmit intelligence to far off places. Only electromagnetic waves can be made to do this. Modulation is extremely necessary in communication ..

The wireless signal consists of radio frequency (high frequency) carrier wave modulated by audio frequency (low frequency). The diaphragm of a telephone receiver or a loud speaker cannot vibrate with high frequency. Moreover, this frequency is beyond the audible range of human ear. So, it is neces..

Need for Frequency Modulation - (i) Various electrical machines and noises cause amplitude disturbance in the transmission of amplitude-modulated wave. This makes the reception noisy. So, there is a need for different type of modulation, which can reduce the noise factor. Freque..

(i) Various electrical machines and noises cause amplitude disturbance in the transmission of amplitude-modulated wave. This makes the reception noisy. So, there is a need for different type of modulation, which can reduce the noise factor. Frequency modulation (FM) was proposed as a mean..

Before all the branches of science were clubbed together under the nomenclature 'Natural philosophy', under which all observations of subjective nature were being carried out and spirit of enquiry was almost non-existent, we were satisfied with simple explanation..

Conclusion - This completes the five chapters under Unit-1 which has taught all those items (such as bricks, mortar, stores, etc., needed for construction of a house) which are the building blocks for observing, studying, understanding and developing the knowledge of science in general an..

Mass is the quantity of matter in the body. Mass is measured by finding out the force needed to change the way the object moves. The greater the force needed, greater the mass of the object. If you push a book, it moves faster than if you push a car with the same force. This is ..

All along when we were discussing about transverse and longitudinal waves the disturbances, which cause them were continuous. But the disturbances always need not be continuous i.e., it might last only for a short duratio..

Since light has a very small wavelength, we need two slits, which send out two continuous coherent waves. Since the two slits are placed very clos..

In order to live and enable ourselves to do everyday work we need energy. The prosperity of a country depends upon the availability of energy. Huge amount of electrical energy is used to run the air conditioners, cold storage and other domestic appliances. A large share of energy is..