Showing posts with label example. Show all posts
Showing posts with label example. Show all posts

Wednesday, 3 January 2018

Electric Potential: definition, explanation, example.

Definition:

"Electric potential is the amount of word done in moving a point test charge from its original position(reference position) to some specific point or position, while moving the charge in direction opposite to direction of field in which charge is present."


Explanation:-

The definition above seem to be difficult to understand the electric potential but I will explain it briefly.
Consider their is a positive point charge A, which have its own electric field around it. And there is another positive test charge B which has no electric field.


 When we will move the test charge B towards the electric field of point charge A then test charge B will move away from the point charge A. This is natural that charge always move from high potential to low potential.


low potential is the area where the charge feels less force while high potential is the area where the force is high.


So to move charge, against its natural movements. we have to provide electric potential or force or to do work. To move test charge B towards the charge A we have to apply some potential which is electric potential, to move the charge from low potential to high potential. So charge B will gain potential energy while moving towards high potential from low potential.

Electric potential is the basic studies of charges behavior with each other. So if you feel there is some type of confusion feel free to comment. The post will be update!

Tuesday, 2 January 2018

Ampere's law: explanation, definition, formula

Definition:-

"Ampere's Law states that magnetic field around a conductor in which electric current is flowing, is directly proportional to the amount of electric current flowing through conductor."

Explanation:

Ampere's law provide us method or formula to calculate magnetic field, produced by electric current.
Just like electric field is directly proportional to the amount of charge, the magnetic field is directly proportional to the amount of electric current from which it is producing.

Formula:-

The most difficult in ampere's law is to derive its equation or make the formula for calculating the magnetic field around a long conducting wire.
So let's start this,
Consider we have long straight conducting wire, when electric current flows through it, the magnetic fields produces around the wire in concentric circle. As shown in below pic.


Every circle is for some specific part of wire and as we move forward in wire, the distance between these circles increases, that mean magnetic field is decreasing. Direction of magnetic field can be found by Fleming's right hand rule.(with direction of current giving)
Now to make the formula, consider there all the parts of wire( which have there magnetic field circuit) having length L and there magnetic field around these parts or elements is B for (every part).

So the equation will become,


And after removing proportionality,

where 𝝁 is the premiability of material or conductor.
B is the magnetic field and delta L is the sum of all length parts and I is the current flowing through the conductor,
sigma shows that the sum of all the length elements or parts with their magnetic field.
Where delta L could be replace by 2πr for particular(single part) length element.
So Then magnetic filed would become,

Saturday, 30 December 2017

Gauss's Law: definition, explanation, formula

Definition:

"Gauss's Law states that, Electric flux around a closed surface is depends upon charged enclosed in that surface and permittivity of free space."

Explanation:


Gauss's law states tell us about electric flux through some closed surface or area,
Electric flux through some area depends upon the charge enclosed by that area and the permittivity of free space in that area.
consider there is a closed sphere and there is charge enclosed in it, the flux out of it or the electric field out of the whole area could be determined with the help of Gauss's law.
Consider we wan to find the electric flux through the green planer area, then it will be simple that electric field lines multiplied by area perpendicular to the lines.
But when there comes a closed surface then there is nothing best except Gauss's law to find electric flux through closed surface (enclosed charge.)
It is not necessary that the surface should be closed sphere it could be any type of closed surface. And we will use Gauss's law to determine the electric flux through it.


Formula:


Mathematically we can determine the electric flux through closed surface by formula,

Where Q is the amount of charge enclosed and Ɛ is the permittivity of free space and 𝛟 is electric flux through the surface.


Wednesday, 27 December 2017

Lenz's law, definition, explanation

Definition:-

"The electric current induced in a circuit or somewhere, always tries to decrease the source which produces it or flow in opposite direction to decrease its effect."  

Lenz's law expand the law of electromagnetism which only tell about induced electric current.

Explanation:-

As we came to know through Lenz's law that the current induced, always tries to do opposite, for the source which is producing it, 


Example:-

lets take an example of a permanent magnet and a coil. 
When we bring the magnet north pole near to the coil there will be change in magnetic field across coil as we move magnet, thus because of changing magnetic field there will induce electric current in it. As we bought the north pole of magnet to the coil, so current induced in coil will start to flow in such a direction that it will make north pole of it towards the permanent magnet north pole, as everybody knows that, like poles of magnet repel each other, hence there, these two north pole will also follow the same rule. And When we will try to bring back the magnet then the current induced in the coil will flow in such a direction, that it will make south pole towards the permanent magnet north pole, where unlike poles attract each other, hence they will attract each other. 
So by doing this current induced in the coil is trying to oppose the source(permanent magnet). By pushing it back when we bring near it(creating north pole towards north pole of magnet) and by pushing it closer when we bring back the magnet(by creating south pole towards the magnet.)

Wednesday, 6 December 2017

Power, its definition, explanation, formula, unit

Definition:-

"Power is define as rate of doing work or Work done per unit time."


Explanation:-

Power is the doing some work, taking less time. Power depends upon doing work and time taken to complete the work. A person have more power will do more work but take less time and person have less power will do less work but will take more time. So this is the concept of power. Work does not depend upon time while power depends upon. so this is the only difference between them.

Formula:-

The formula for power is work done per unit time.

Power = Work / time

as work is equal to 

work = F.d

so power would have,

Power = Force.displacement / time
P = F.d / t

Unit:-

Unit of power Watt  is define as " If one joule of work is done in one second then power will be one watt"
P = F.d / t
Watt= Newton. meter / seconds
Watt = joule / second.




Friday, 1 December 2017

Waves and types of waves

Definition:-

"Wave is the transfer of energy from one place to another place without the transfer of matter or body."

Explanation:-

Wave only transfer energy or disturbance from one place to another place with transfer of matter, they travels through some medium.
The above shown diagram is of wave. As seen that there also some parts of  waves. Crest and Trough.
The highest point of wave is known as crest and lowest part is known as tough, while rest position is the middle position.

Examples:-

1.When you throw the stone in the lake, then waves starts to travel arround the hit point of stone on water. these waves carries some energy, when you will put your finger in these waves you will some force.
2.Wind(Air flowing) is a kind of waves they can move away papers like stuff means carry some energy.
3. You speak, your voice travels to the other in the form of waves, as they feel sound means your voice has energy.

Types of Waves:-

there are three basics types of waves:-

1.Mechanical Waves act as the propagation of a disturbance through a material medium due to the repeated periodic motion of the particles of the medium about their mean positions, the disturbance being handed over from one particle to the next.

2.Electromagnetic Waves
 are the disturbance, which does not require any material medium for its propagation and can travel even through vacuum. They are caused due to varying electric and magnetic fields.

3.Matter Waves
 are the waves produced in electrons and particles

Thursday, 30 November 2017

Work

Definition:-

"Work is the product of force and the distance covered by a body due to force applied on it"


Explanation:-

In physics work is done on a body, when we apply some force on it and it covers some distance in the direction of force.
Work is not done until body is not covering some distance whether force is applied on it or not, body has to cover some distance in order to get work done. or work will not be done until force will not be apply on it whether it is covering some distance or not. so both things are necessary.

Example:-

1.When you try to push the box by applying force on it and box start to move in direction of force, then your are doing work.
2.When you try to push the wall then you apply force but wall doesn't move, so you are not working (According to physics).

Unit:-

The Sl unit of work is joule J

Formula:-

Work also have an formula to calculate it mathematically,

W=F.d.cosθ

As define work is the product of force and distance and the angle between them. 


Conditions:-


1.This cos shows that when force applied and distance covered is in same direction then angle will be 0, where cos(0)=1, hence work will be maximum.
2. When force applied and distance cover will be perpendicular to each other than angle will be 90 and cos(90)=0, hence work will be 0.
3. When force applied and distance covered is in opposite direction  then work will be negative as, angle will be 180 and cos(180)=  -1.


Tuesday, 28 November 2017

Centripetal force

Definition:

"Centripetal force is a force, which keeps a body moving in a circular path and that force acting towards the center of that circular path."

Explanation:

A body never automatically or itself moves in a circular path it, there is always a reason or some force that causes it to move in a circular path and that force in general is known as a centripetal force. and that force is always directed towards  center. it means force is from the center of circular path that causes it to move in a circular path.

Example:

You tries to move a string in a circular path. one end of it is in your hand and other is tied with a stone. and consider that stone is a body. you provide force from your hand which is at the center of circular path in which stone(body) is moving.

Formula:

 

This equation shows that force depends on the mass of body and the velocity by which it is moving in path and the distance(r) between the center of circular path and body.



Sunday, 6 August 2017

laws of motion. explanation

There are 3 laws of motion. It is described(invented) by Newton.
They're:

1.First law of motion (law of inertia)

"An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force"


Explanation:

It means that a body in rest condition, will remain in rest until a force will act, whether is the Force by human, air or from anywhere.


 Example:

 A book will remain on table unless you will pick it or it is blow away by some wind. And body will remain in motion unless some force will stop it. I.e. A car will never stop until you break it.

2. Second law of motion

" Acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object."


Explanation:

It means that if a body has change in its velocity(speed) or position, then its depend upon the total force acting upon him and the mass of the body. It is also known as law of inertia. Having low mass will demand less force for change in its speed.

Example:

If you will apply same force on car and then truck. Car will have more acceleration than truck because car have less mass with respect to the truck.

Formula:

acceleration = Force/mass (a=F/m)

                                        F= a.m



Third law of motion:-

"For every action, there is an equal and opposite reaction."

Explanation:-

Its means that if there will be action from some body to other body, there is always a re-action from other body equal in force but opposite in direction.

Example:-

If you throw the tennis ball to the wall then ball will return back to you with same speed. You throw the ball it is an action the ball returns it is an reaction and in opposite direction.