## Conservative and Non conservative forces

Some Points about Conservative forces and Non conservative forces
1) Potential energy are defined for Conservative forces
2) An object that starts at a given point and return to the same point,then
net workdone by the conservative force is zero while in case of non conservative force ,it will not be zero

## Photons

It only participates in EM interactions. Strong and weak interactions are not in photon domain of experience. When particle annihilate with anti particles the end product is often protons.Photon is its own anti particle.

## How to use Gauss’s Law to find electric field

We all know that Gauss’s law is basically the relation between the charge distribution producing the electrostatic field to the behaviour of electrostatic field in space. Also Gauss’s law is based on the fact that flux through any closed surface is a measure of total amount of charge inside that surface and any charge outside that surface would not contribute anything to the total flux.

## Quick Vector Algebra Summary

Here in this post we will go through a quick recap of vector algebra keeping in mind that reader already had detail knowledge and problem solving skills related to the topic being discussed. Here we are briefing Vector Algebra because concepts of electrostatics , electromagnetism and many more physical phenomenon can best be conveniently expressed using this tool.

## Overview of electrostatics and electricity

Electrostatics involves electric charges namely positive and negative charges, the forces between them which is known as electric force , the field that surrounds them, and their behavior in materials. Coulumb’s law is the simple relation that governs electrostatic interactions and the field around the charges is described using the concept of electric field. Coulumb’s law is a inverse square law which gives the force between two charges kept at some distance (say r ) apart from each other. Like Coulumb’s law, law of gravitation is also a inverse square law but gravitational interactions are only attractive in nature and electrical interactions are attractve as well as repulsive depending on the nature if interacting charges. Charges of same kind repel each other and charges different kinds , i.e. one charge positive and other negative , attract each other. One more thing electric interactions are much more stronger then gravitational interactions and gravitational force are almost negligible in comparison to the forces of electric origin.

## CSIR UGC NET JRF & LS Physical Science Syllabus

CSIR-UGC National Eligibility Test (NET) for Junior Research Fellowship and Lecturer-ship Physical Science Syllabus
PART ‘A’ CORE

I. Mathematical Methods of Physics
Dimensional analysis. Vector algebra and vector calculus. Linear algebra, matrices, Cayley-Hamilton Theorem. Eigenvalues and eigenvectors. Linear ordinary differential equations of first & second order, Special functions (Hermite, Bessel, Laguerre and Legendre functions). Fourier series, Fourier and Laplace transforms.

## Physics books for CSIR-NET/JRF and GATE

This is the list of few books recommended for those preparing for net/jrf in physics . It is hard for a person to collect these many books so i would advise you to go through these books while doing your masters in physics and make yourself appropriate notes for further reference and study.

Classical mechanics

1. Classical Mechanics by Herbert Goldstein
2. Classical mechanics by Gupta and Kumar