The two main domains of interest in Physics are macroscopic and microscopic. The macroscopic domain includes the study of Phenomena involving objects offinite size, this makes up classical Physics, developed upto the year 1900. The microscopic domain includes the study of Phenomenon involving molecules, atoms, nuclei, electron and other. elementary particles. This makes up modern physics developed after the year 1900. Overall Physics has played a key role in the development of many other branches of science.
(i) Mention the different branches of classical Physics.
(ii) What are limitations of classical Physics?
(iii) Which theory explains properly the microscopic domain.
(iv) What does the branch of Physics, Thermodynamics deals with?
(v) Explain how Physics is in relation to mathematics?

Physics is a basic discipline in the category of natural sciences. It refers to the study of the physical world and it is devoted to the study of nature and natural phenomenon. In the study of physics, there are two principal thrusts: unification and Reductionism. Unification means attempt to explain the diverse physical phenomenon in terms of a few concepts and laws, while reductionism attempt to derive the properties of a bigger, more complex system from the properties of its constituent simple parts.
(i) Mention the origin of the word 'Physics' and write its meaning.
(ii) Name some phenomena which are unified by Newton's law of gravitation.
(iii) Name the equation that unified basic laws of electromagnetism.
(iv) What reductionism has done in thermodynamics to explain some macroscopic quantities?
(v) What are main five branches of Physics?
(vi) What is Physics?

Physics has revealed that all the forces occuring in different contexts arise from a small number of fundamental forces in nature. Though the origin of derived forces is complex, yet they can be understood in terms of the fundamental forces which govern the macroscopic as well as microscopic world. These fundamental forces are gravitational force, weak nuclear forces, electromagnetic forces, strong nuclear forces. Among these gravitational and electromagnetic forces have some common characteristics like being central, conservative, long range and obeying inverse square law while weak nuclear forces and strong nuclear forces are of nuclear origin, microscopic and very short range attractive forces. All these forces govern the diverse phenomena of physical world.
(i) What is the relative strengths of four types of basic forces in nature?
(ii) In which phenomenon does weak nuclear forces involve? Explain.
(iii) What are graviton and photon?
(iv) What does the inverse square law represent? Show graphically.
(v) What is range of weak nuclear force and strong nuclear force?