CBSE Class 11th Physics Notes for Chapter 1 Physical World

​            CHAPTER 1 PHYSICAL WORLD
 
Physics deals with the study of the basic laws of nature and their manifestation in different phenomenon. The basic laws of physics are universal and apply in widely different contexts and conditions.
There are two domains of interest in physics: macroscopic and microscopic. The macroscopic domain includes phenomena at the laboratory, terrestrial and astronomical scales. The microscopic domain includes atomic, molecular and nuclear phenomena.
 
FUNDAMENTAL TYPES OF FORCES

1. Gravitational force: The gravitational force is the force of mutual attraction between any two objects by virtue of their masses. It is a universal force experienced by every object in this world.
2. Electromagnetic force: Electromagnetic force is the force between two charged particles.
3. Strong nuclear force: The strong nuclear force binds protons and neutrons in a nucleus.
4. Weak nuclear force: The weak nuclear force appears only in certain nuclear processes such as β- decay of a nucleus.

 
The physical quantities that remain unchanged in a process are called conserved quantities. Some of the general conservation laws in nature include the laws of conservation of mass, energy, linear momentum, angular momentum, charge, parity, etc.