[Physics Class Notes] on Basic Physics Pdf for Exam

Basic Definition of Physics

Basically, Physics is the knowledge of nature. If we want to understand the matter at miscellaneous levels, let’s say both macroscopic and microscopic levels, basic Physics turns out to be a gold mine to study their nature of motion, behavior in low and high temperatures, the kinetic energy of molecules, and much more.

Physics helps us study the motion, behavior of matter through space and time. On the whole, it is a natural science that deals with all the related entities of force and energy.

Definition of Physics

Physics is a natural science that deals with matter and energy and interactions of matter with one another. It also deals with all physical processes and phenomena of a particular system. 

Let’s suppose that there is a container filled with gas and on the top of this container, a frictionless movable piston is fitted. Now, on passing heat to this system, the gas expands. So, what is the Physics behind this expansion?

Well! When the heat is added, there is a temperature rise in the gas, which leads to the rise in the internal energy of the gas, and that internal energy is the kinetic energy. Initially, these gas molecules had a stored internal potential energy and they gain entropy because this potential energy converts into kinetic energy. This results in the expansion of the gas, and therefore, uplifting of the piston. 

So, what do we infer from the above statement?

Well! Whatever energy was supplied got totally transformed into work, i.e., no wastage of energy. The same scenario is observed in an imaginary engine, viz: Carnot engine.

 

                         

So, our first law of thermodynamics (energy is transformed without creating or destroying it) with the help of Physics.

Definitions of Physics

Let’s have a look at a few Physics definition and branches:

1. Forces in Nature

Every day we observe the applications of forces in one or other objects like contact forces between two objects, frictional force between your shoes and the road, forces exerted on strings and springs, viscous forces, electrostatic and magnetic forces and much more; all these forces we encounter at the macroscopic world are manifestations of the following two types of forces:

• Gravitational forces

• Electromagnetic forces

However, at the microscopic level, we have two basic types of forces:

• Strong nuclear forces 

• Weak nuclear forces

2. Ampere

The unit Ampere was named after a French Physicist and Mathematician named André-Marie Ampère. It is the SI unit of current. 

The International System of units describes ampere in other terminologies by assuming it as the electromagnetic power an electrical circuit holds through which the current is flowing when the conductor is subjected to the potential difference across its ends. The dimensional formula for the current is [A].

Branches of Physics

There is a big list of branches in Physics basic, let’s enlist these:

• Mechanics

• Modern physics

• Thermodynamics

• Classical physics

• Electricity

• Magnetism

• Geo physics

• Plasma physics

• Optics

• Sound and oscillation

• Chemical physics

• Engineering physics

• Quantum physics

• Electronics

• Nuclear physics

• Particle physics

• Biophysics

• Astrophysics

• Condensed matter physics

• Solid-state physics

Let’s discuss the basics of Physics in detail:

Physics Definition and Branches