The flow of charge in an electric circuit signifies the existence of electric current in that circuit. We can define electric current as the rate of flow of electric charges (electrons) in a conductor (for example copper or metallic wire). Flow of charge definition The flow of charge is the process of supplying or adding […]

# Physics

## Difference between resistance and resistivity

In this article, we will learn about the difference between resistance and resistivity. Students first come across these terms while studying Electricity where the concept of electric current, resistance and resistivity are introduced. For the basic introduction visit our notes on electricity. TLDR – Too Long Don’t ReadBoth resistance and resistivity describe how difficult it […]

## What is graph in physics?

In this article learn about the what is graph in physics and how to plot a basics of graphs in physics. Here you will learn aboutÂ Why we need graphs What are graphs and How to plot graphs After reading this article students would be able to define graphs and plot graphs using data on […]

## What is trajectory

Introduction to the concept of trajectory A trajectory is the path followed by an object with mass in curvilinear motion (curved path) as a function of time. Mathematically ,It is defined by the equation in x-y coordinates. A famous example would be projectile motion like the ball thrown an angle or a bullet fired from […]

## How to find work done by Multiple forces acting on a object

This can be done in these simple steps

1) First draw a free body diagram of the body showing all the forces on it.

2) Carefully choose a X-Y coordinate system so that direction of the motion or direction of force lies in X or Y direction. This will simplfy the Problem

3) Applying Newton’s law find out any unknown forces

## Reverse breakdown in PN Junction

When a PN junction is reversed biased it allows very small current to flow through it. This current is due to the movement of minority charge carriers and it is almost independent of the voltage applied.

If reverse bias is made too high, the current through PN junction increases abruptly and the voltage at which this phenomenon occurs is called breakdown voltage .

## How to Calculate the force given potential energy

For one dimensional motion, the force can be found from Potential energy using following formula

## Newton’s law Interesting conceptual questions

Question: When a person walks on the floor? which direction force is applied by the person to move forward?

Question: According to Newton’s third law,each team in a tug of war pulls with equal force on the another team

What then determine which team will wins it