ENERGY

Energy is the basic necessity for the economic development of a country. Many functions necessary to present-day living grind to halt when the supply of energy stops. It is practically impossible to estimate the actual magnitude of the part that energy has played in the building up of present-day civilisation. The availability of huge amount of energy in the modern times has resulted in a shorter working day, higher agricultural and industrial production, a healthier and more balanced diet and better transportation facilities. As a matter of fact, there is a close relationship between the energy used per person and his standard of living. The greater the per capita consumption of energy in a country, the higher is the standard of living of its people. Energy exists in different forms in nature but the most important form is the electrical energy. The modern society is so much dependent upon the use of electrical energy that it has become a part and parcel of our life. In this chapter, we shall focus our attention on the general aspects of electrical energy.

Energy may be needed as heat, as light, as motive power etc. The present-day advancement in science
and technology has made it possible to convert electrical energy into any desired form. This has
given electrical energy a place of pride in the modern world. The survival of industrial undertakings and our social structures depends primarily upon low cost and uninterrupted supply of electrical energy. In fact, the advancement of a country is measured in terms of per capita consumption of electrical energy.
Electrical energy is superior to all other forms of energy due to the following reasons :

(i) Convenient form.Electrical energy is a very convenient form of energy. It can be easily
converted into other forms of energy. For example, if we want to convert electrical energy into heat,
the only thing to be done is to pass electrical current through a wire of high resistance e.g., a heater.
Similarly, electrical energy can be converted into light (e.g. electric bulb), mechanical energy (e.g.
electric motors) etc.

(ii) Easy control.The electrically operated machines have simple and convenient starting, control
and operation. For instance, an electric motor can be started or stopped by turning on or off a switch.
Similarly, with simple arrangements, the speed of electric motors can be easily varied over the desired
range.

(iii) Greater flexibility.One important reason for preferring electrical energy is the flexibility
that it offers. It can be easily transported from one place to another with the help of conductors.

(iv) Cheapness.Electrical energy is much cheaper than other forms of energy. Thus it is overall
economical to use this form of energy for domestic, commercial and industrial purposes.

(v) Cleanliness.Electrical energy is not associated with smoke, fumes or poisonous gases.
Therefore, its use ensures cleanliness and healthy conditions.

(vi) High transmission efficiency.The consumers of electrical energy are generally situated
quite away from the centres of its production. The electrical energy can be transmitted conveniently
and efficiently from the centres of generation to the consumers with the help of overhead conductors

known as transmission lines