# Physics

## The International System of Units

People from various countries use three different systems of units for measurements. These systems have been listed below, along with their base units for length, mass, and time: But technically, the current internationally accepted system of units for measurement is the Systeme Internationale d’ Unites, abbreviated as SI and generally called the International System of Units.…

## Einstein Field Equations

The Einstein field equations or EFE are the 16 coupled hyperbolic-elliptic nonlinear partial differential equations that describe the gravitational effects produced by a specified mass in the theory of general relativity. Essentially, they relate the geometry of spacetime to the distribution of matter within it. Because of the symmetry of Gμνand Tμν, the actual number…

## Significant Figures: Definition, Usage and Examples

"What are Significant Figures?", "What are they used for?", "What is their significance?" Students often ask these questions because why would you want to identify significant numbers, if you can do mathematical calculations without them, right? Where the idea of using significant figures might come off as unnecessary, it is a crucial concept that you…

## What is a Transistor and How does it work?

A transistor is a semiconductor gadget used for amplifying or switching electronic signals and electrical power. It is built with a single piece of semiconductor material and consists of three terminals connected to the external circuit. If you provide any voltage through one end of a transistor, it changes the current flow through the rest…

## Bosons

In particle physics, a boson is a type of particle that obeys the rules of Bose-Einstein statistics. These bosons also have a quantum spin with contains an integer value, such as 0, 1, -1, -2, 2, etc. (By comparison, there are other types of particles, called fermions, that have a half-integer spin, such as 1/2, -1/2, -3/2, and so on.)…

## The Four Fundamental Forces of Nature

Intuitively, we are all familiar with the concept of force due to our experiences in everyday life. There are many kinds of forces seen in the macroscopic domain, such as gravitational force, friction, viscous force, elastic force, and much more. Similarly, in the microscopic domain, such as electric force, magnetic force, nuclear force, and so on. In…

## Standard Model

One of the most startling discoveries over the 20th century was how many elementary particles exist in the universe. Though the concept of fundamental, indivisible particles goes back to the ancient Greeks (a concept known as atomism), it wasn’t really until the 1900s that physicists began to explore what was going inside matter at the smallest levels. In…

## Special Relativity

In 1905, Albert Einstein published (among other things) a paper called "On the Electrodynamics of Moving Bodies” in the journal Annalen der Physik. The paper presented the theory of special relativity based on two postulates: Einstein’s Postulates There were two key postulates: The paper presents a more formal, mathematical formulation of the postulates. The phrasing…

I don't feel that I should explain the importance of kinematics in Physics. Kinematic equations form the very foundation of any question you intend to solve in physics. Be it uniform rectilinear motion or rotational motion, these equations will always help you to find the correct answer. Whether you are preparing for NEET or JEE…

## Boltzmann Constant

First of all, there are constants named after Ludwig Boltzmann, the first Boltzmann constant and the second Stefan-Boltzmann constant. We will discuss the first one here. Both Boltzmann constants play vital roles in Physics and Astronomy. Role of Boltzmann Constant in Physics Boltzmann Constant unites the macroscopic and microscopic worlds, and provides the basis for…

## Symmetry in Physical Laws

'Symmetry' has a special meaning in physics. A picture is said to be symmetrical if one side is somehow the same as the other side. Precisely, a thing is symmetrical if one can subject it to a certain operation and it appears exactly the same after the operation. For example, if we look at a…

## Macrostates and Microstates and their relations with Thermodynamic Probability

In this article, we will explore and define macrostates and microstates in statistical physics with examples and illustrations. Macrostates and Microstates Consider some (4, say) distinguishable particles. If we wish to distribute them into two exactly similar compartments in an open box, then the priori probability for a particle of going into any one of…