Electronics plays a major role in almost every sphere of our life-our homes, factories, offices, banks, shops and hospitals. It is being used more and more in entertainment, communication, defence, industrial sector, medical sciences, instrumentation etc. Its importance increases with every advance in technology and with the urge to computerise human tasks and industrial processes.
Light is central to human perception. Light from all directions bombards our eyes, and our brain constructs images of objects by processing this information. As a consequence, we perceive shapes, textures, colours and motion of objects. The play of early morning sunlight on the snowcaps of mountains, the left-handed image of a mirror, the colour of crystals or the distorted view of objects under water has revealed to us deep secrets of nature. This is, perhaps, why the study of light, the phenomena associated with it, and its interaction with matter has engaged human mind for over three thousand years.
The first level physics laboratory course is an exercise to develop basic experimental skills in a student. In the second level laboratory course IGNOU wish to cultivate confidence in students in handling sophisticated instruments, apart from generating ability to overcome difficulties when an experimental arrangement does not work. Moreover, interpreting and analysing data should sharpen student's scientific skills.
Today we live in a world dominated by electrical appliances. Continued innovations in technology have revolutionised our life style. And it is highly satisfying that such a wide variety of devices operate on a few simple electromagnetic principles.
Energy is intimate to our existence. The energy that cooks our food, lights our houses and operates machines appears in its manifestation as heat released in burning of wood, coal, gas or oil. What is heat? How can we specify the direction of its flow? The answers to these and other related questions fall in the domain of thermodynamics. This subject came into existence on phenomenological basis long before we knew the nature of matter. Syllabus for IGNOU BSc Physics facilitate two distinct approaches to learn this subject. The classical approach is based on some postulates derived from experience. In the statistical approach, on the other hand, the firm physical and statistical basis of thermodynamics is demonstrated by relating the properties of bulk systems to the behavior of their elementary constituents.
Change is the law of nature. We all know that most things evolve with time. They are also diverse and non-uniform in space. The evolution in space and time is best described in a quantitative way in terms of differential equations. The oscillations of a simple pendulum, as iil an old fashioned wall clock, propagation of sound and light waves enabling us to hear and see, excitation and deexcitation of electrons in atoms which generate light waves, complicated interactions in chemical reactions, growth of bacteria feeding on rotten foodstuff, foxes eating rabbits who eat grass, and similar otherphysical problems can be modelled by differential equations.
Mathematics is the language of physics. It permits us to discuss the laws of physics and their consequences in an attractively simple and compact manner. As Galileo so delightfully expressed: "The great book of nature lies ever open before our eyes, but it is written in mathematical characters." Experience tells us that there has been a fascinating interplay between physics and mathematics all along.
Observation and experimentation are the two characteristic features of science. Prior to Galileo, scientists based their theories on speculation and aesthetic preferences. He broke away from this tradition. Ever since, it has become a standard method of science to accept theoretical predictions only if repeated observations and precise measurements provide enough evidence. Indeed as Lord Kelvin so aptly put it. "When you can measure what you are speaking about and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind."
The phenomena we normally observe in nature can broadly be classified into two categories: those concerned with matter and those concerned with waves. Physics courses usually begin with discussion of phenomena dealing with mechanics of matter and properties of matter. Next comes the phenomena of waves. Of our five senses, two deal with the waves — hearing and seeing. Our contact with the external world is mainly through these two senses.
We live in a Universe of continual motion. Electrons swarming around atoms in matter, buses speeding along highways, planets orbiting the sun, the stars and galaxies rushing apart are all examples of matter in motion.
The branch of physics dealing with the motion of bodies as well as bodies at rest or in equilibrium is called mechanics. Since motion is such an important feature of the world around us, it is the logical subject to begin the study of physical phenomena. Therefore, we are offering this course entitled Elementary Mechanics as the first elective in physics. As the title suggests, in this course you will study elementary concepts and laws of mechanics, including the laws or conservation of linear momentum, angular momentum and energy.