learn Physics Free best concept

Education for all Physics and Telecommunication technology Free best concept

The Education Big Message of this Website must read !!!

The Education system is not good, The concept of education is not good, The education importance is not good.You will ask why? Then I will ask a question. How many Peoples get up in the morning as a intention that today I will learn something new. Can you answer the question? Well I can answer as per survey record only 6% people have intention every day to learn something new. Now important point, why such a less percentage of people? The answer is most of the people have no purpose of life and education importance.

All behind this is true meaning of education system is not good, Lets to elaborate this, The teaching style of teachers are not good and that is reason students are not participate in the class actively. Students are not getting interest in whatever they are learning.

Concept of Education

                                                 

Education Importance

                                           

   
Teachers inter in the class room and just write down the menu of syllabus, you have to study in this subject xyz  and will be cover one by one without giving any practical application and uses of any topic of the syllabus menu. Incompetent faculty in colleges, Actually colleges are now became business for more profit they hire low salary base faculty, This is education system . This is true meaning of education, This is the concept of education . Believe me that is the main reason students don’t participate in the class actively. Because they don't know the importance of education they are studying.

Well Student level of preparation and level of aspiration ground and sky gap. Today education is for degree not for knowledge .Well filled mind not well formed mind and this well filled mind will give you nothing.Incompetent faculty teaching with conversational theoretical classroom based approach. 
Students don’t know why they are studying this topic and what they are studying in this topic, What is the practical uses of that topic in life. You can ask this question but most of the student don’t know what they are studying and why they are studying.

Where they can use this knowledge in their daily life .This is main reason of confusion in study and life.  

Their goal is not clear, what to do and what they can do better.

Instead of giving the education syllabus menu, Teachers should emphasizes the practical uses and applications of the topic before teaching that topic. So that teachers can attract the attention of Students in the class room .

Due to this type of education system students are just memorizing the things or topic not understanding the things or topic fully. So Confusion continue in study and life.

To make education learning practical, application and its uses in life it will require more effort from each of us to change the present education system.

So I am doing my effort in the field of Physics and Telecommunication technology please come and join this effort to make it successful .So that when everybody get up in the morning as an intention to learn something new and that percentage will increase from 6%  then successful person percentage will increase in the world.

I don’t know what do you mean by success ? but my opinion Success is freedom, your own choice for your life. Do what love to do, it will give you success in your life.   
                                                   

 
Share Knowledge of science Physics and technology Telecommunication to Society those who want to learn concept of Physics and Telecommunication in easiest way free of cost you will never forget as simple and practical .If you hate Physics and technology there may be some reason to hate and it is as simple you have not studies the way your brain want to accept.you have learnt from wrong teacher. after a long experience here i will teach you the way you never study before and never thought Physics is as simple.it will be Physics magic, each and every topic will be covered with key concept in depth analysis based upon the facts and experience close visualization for topic you will study.

                                                               

Study of Nature 

                                                                                                                    

                         

understand our physical world

Understand our physical world 

Hello how much beautiful is our physical world, you will learn here hidden concept of physical world .This is first chapter of class XI Physics, Study of Physical world is actually starting of Physics because you know study of nature is Physics. 
So it is very important to understand physical world. A famous  saying, perhaps you know "well began is half Done". its meaning is if you start well that indicate 50% of your work is done. So if you want to really learn Physics, You must first understand physical world.This is very interesting topic,You will really enjoy to learn this topic .This is small topic but very important for concept point of view and basic understanding, In other words I can say. This  is pillar of Physics, So lets start, what is in this beautiful physical world for you to learn ? 

Physical World meaning world of Physics ( Physics Ki Duniya )   

Very first i will Welcome you to Physics World.

Understand our physical world 

                 

How to study physics right direction 

We will see here the right method of physics study so that it will be easy for our study physics very interesting

                                                  

How to Study physics

                                                         

Know Important concept for Force

What we study maximum in Physics ?

                     

                                       

Know Important concept for Force 

                               

satellite orbital velocity

Satellite orbital velocity

Satellite is an object which is moving around the Earth. There are two types of satellite one is natural satellite made by nature (Moon) and other is artificial satellite which is made by men.

One important point i want to make it clear here from childhood you learn that every planets move around the Sun, Moon moves around the Earth, even any picture of solar system shows all planet moves around the Sun including Earth.

But you will shock, When i will tell you this is technically wrong all planet and Moon does not moves around the Sun and Earth.

Then you will ask me if all the planet does not moves around the Sun, which is that body around it all planet moves. And your next question will be if it is wrong then why teach like this wrong concept in book ?

Well actually books and pictures shows all planets moves around the Sun is correct, so that you can easily understand the solar system behavior without knowing the technical point.

Now here you will learn around which all planet moves and even Sun moves around which,  

and also why do you teaches that all planet moves around the Sun ? 

Planets and Stars moves around the common centre of mass, This common centre of mass is also known as barycenter to understand barycenter you must know centre of mass you can refer my previous post center of mass concept.

Centre of mass is that point at which whole mass of the body or system lies at that point, means body is  balanced, sometimes it can lies outside the body, some time between two masses and sometimes near the heavier mass depends upon the mass quantity and its shape and size, for more details refer above link.

                                                                     

        

                                                                                 

bandwidth definition

Bandwidth definition

Today you will enjoy to learn something new about bandwidth, You will learn in this post actual meaning of bandwidth, What is bandwidth ? examples of bandwidth, types of bandwidth, how bandwidth is measured ? What is bandwidth limit ? What is device bandwidth ? What is difference between bandwidth and speed ? You will learn all about bandwidth in easy way, so that you will never forget bandwidth, lets start.

What is bandwidth ?

In communication when you  are sending signals, So first you should understand what are signals ? The signals are variation of voltage, but made of what ? you can think from where this variation comes ?.

The answer is simple, it is message signal created  by the source,like if you are sending your voice and  communicating  it. Now your voice is made by vibration of your vocal cords, which start the wave, this wave is again converted into electrical signal in the form of voltage.

This frequency is a constant and remains constant, whether it is converted into electrical form which is voltage.What types of frequency generated by your vocal cords ? there is a particular value of frequency generated by your vocal cords.

It is not an unique and single value of frequency generated by your vocal cords, It is a combination of frequencies generated by vocal cords.

So there are so many frequencies which are generated at a time, because there are so many particle of vocal cords and all are vibrating with different frequency , but there is a mean frequency all of them.

Hence there are two things one is all frequencies and other is a mean frequency, all there frequencies are around the mean frequency.  

Suppose you are speaking and the mean frequency is 300 Hz, May be there are certain lyrics in your voice, which are at 250 Hz and 350 Hz, See there is a range of frequencies in your voice which is  250, 300, 350 Hz. This range is called bandwidth of your voice see below picture.

                                                                   

Bandwidth

                                                                     

escape velocity

Escape  velocity

In the universe massive bodies have bounded all small bodies with bound energy, Now to escape small bodies from the surface of massive bodies gravitational field influence, You must required a minimum velocity to free small object from massive bodies surface, this minimum velocity is know as escape velocity.

What is escape velocity 

Escape velocity of a planet is that minimum velocity given to an object on that planet due to which it will just escape the planet and will never come back again on that planet.

When you through an object from the surface of the Earth, it goes up some height and then start fall back towards  the Earth surface, This happen due to gravitational field attraction by Earth around it.

Earth gravity acts vertically downward continuously and due to this object speed decrease continuously at per second  9.8 m/s and finally reaches at a height at which final speed becomes zero, but gravity acceleration acting downward and then object start coming back towards surface of the Earth similarly every second speed increase 9.8 m/s and finally reaches the Earth Surface. 

But when you will through the object with so much high velocity that it will reach very high where gravity pulling effect vanishes and then the object velocity becomes zero that that point object will stop in space and will never come back on the Earth surface that minimum through velocity is escape velocity.

See the below picture.

                                                                 

Escape Velocity

                                                                       

gravitational potential energy

Gravitational Potential Energy

Gravitational potential energy is an important concept, This energy is invisible you can not see, so most of the time students confused, But in this topic you will learn some new hidden concept about gravitational potential energy, I ensure you after learning this post your all doubt and concept will be clear, Each and every concept about gravitation potential energy will discuss, What is gravitational potential energy ? How gravitation potential energy is calculate and what is it real meaning ? Why gravitational potential energy value is negative What is potential energy at infinity ? So lets start.

What is gravitational potential energy ? 

Actually gravitational potential energy is not define directly any meaning, it define in terms of change in potential energy, so for change in potential energy calculation, you need to do some work.

Hence gravitational potential energy is define as work done bringing a mass from infinity to a certain point in gravitational field. This gravitational field is created by another source mass. If you don't know about potential.

Refer my previous post about gravitational potential concept

See gravitation potential energy is not for a single body or mass, It is always for a system means between two or more masses gravitational potential energy is stored in the system of masses .If you will ask what is gravitational potential energy for a single mass ? 

Well for a single mass gravitational potential energy is always zero. Wait you will see how it is zero ? As i have mentioned that potential energy is work done then who does this work ? Well external agent like you or gravitational force both does this work but when work is done by external agent then work value is positive and when work is done by gravitation force its value is negative.

Mathematical expression change in potential energy (∆U) = (-work done by internal conservative force) or Uf - Ui  = ∆U=  (-work done internal conservative force).

Now what is conservative force ? conservative force is that force in which wok done depend upon initial and final position it does not depend upon the path, like gravitational force, spring force are example of conservative force.

So Conservative forces only posses potential energy, non-conservative force like friction does not posses potential energy.

you must remember during the work done velocity must remain constant hence kinetic energy must not change.

Concept of gravitational potential energy 

Potential energy at infinity (∞) for any types of mass system or any mass configuration is assumed universally zero by scientist. Hence you use the above formula, Uf - Ui  = ∆U=  (-work done internal conservative force)

So Uf - U∞   = (-work done by gravitational force bringing each mass from infinity) so

Uf -0 = (-work done by gravitational force bringing each mass from infinity)

Uf  = (-work done by gravitational force bringing each mass from infinity) important again i am telling potential energy is not for mass, it is for design or configuration which is bringing from infinity to a certain point. see below picture.

                                                           

Gravitational potential energy

                                                                         

gravitational force and gravitational constant

Gravitational force and Gravitational constant

Today our topic is very important and interesting because you will know the fact of gravitational force, which you will be not knowing before,Here you will learn hidden facts of gravitational force,I hope that you will enjoy this topic to know the hidden concepts of gravitational force. Here in this topic your all doubt and confusion will be clear, After reading this complete post, I ensure you will feel that you have learned some hidden concepts about gravitational force, which you were not learned before, so lets start to know gravitation force facts.

                                                                           

Gravitational force 

Gravitational Force law history facts 

As you know and learned by your teacher saying that an apple was fall on head of  great scientist Newton, He did not ate that apple but started to think , Why did this apple fell down on the Earth ? And after that this gravitational force law was invented by Newton.

This is wrong story but trended in society, You can think and imagine yourself that due to an apple fall no body can make a big universal truth law. This law was not made by a simple apple fall, You can search on Internet the history of gravitational law, This is documentary type of topic, If i will explain in details then this post will become very long, So in short and important contribution of all scientist to develop gravitational law will discuss.

                                                                      

                                                                       

conservation of momentum

conservation of momentum

Conservation of momentum is very important topic of Physics because conservation of momentum concept state second law of Newton.We will see how Newton's law was derived from conservation of momentum.In our previous post we have already studies about conservation of momentum formula and its basic concept, You can refer the previous post for basic concept and definition of conservation of momentum concept for conservation of momentum. In this topic we will cover the application of conservation of momentum as well as its numerical problems.So lets start.

Conservation of momentum for a system

Linear conservation of momentum, we know that any rigid bodies system is made by collection of many small particles, Take an example of rotating wheel of a car, Another example rotating ceiling fan.

When we observe this rotating bodies, Then we found that there are many small particle, Which are rotating with different speed in different radius.

If anybody ask find the speed of the rotating wheel,Then what will be your answer, Which small particle speed you will answer this is really difficult, So to make this simple, we answer the speed of center of mass of the rigid body.

Because whole mass of the rigid body is concentrated at the centre of mass. we have already learn in previous post . So whole body is consider as a system and its internal small particle conservation of momentum gives the whole body conservation of momentum.

We will see how these two conservation of momentum is same, just wait see the below picture.

                                                                     

Conservation of momentum

In Centre of mass post we have studies that how to find the centre of mass for small point mass, So i am just using that concept.

We know that centre of mass general formula is given as rcom (centre of mass) .

rcom  = (m₁r₁+m₂r₂+m₃r₃+......................+mₙrₙ)/(m₁+m₂+m₃+................+mₙ)

Now  differentiate this equation with respect to time on both side then we will get 

d(rcom)/dt  = (m₁dr₁/dt+m₂dr₂/dt+m₃dr₃/dt+..............+mₙdrₙ/dt)/(m₁+m₂+m₃+..........+mₙ)

we know  dr/dt  = velocity = v so we can write the above equation as 

Vcom  = (m₁v₁+m₂v₂+m₃v₃+..............+mₙvₙ)/(m₁+m₂+m₃+..........+mₙ)

 Now arranging the equation we can write like this.

(m₁+m₂+m₃+..........+mₙ)Vcom  = m₁v₁+m₂v₂+m₃v₃+..............+mₙvₙ

 (m₁+m₂+m₃+..........+mₙ) = total mass of rigid body =M as shown in above picture  so we can write as 

MVcom  =  m₁v₁+m₂v₂+m₃v₃+..............+mₙvₙ now as shown in above motion picture momentum of different small particles m₁v₁, m₂v₂, m₃v₃  hence If we want to write momentum of the system can write  Psystem  = MVcom . p = mv

Whenever we want to write momentum of a rigid body then we take whole mass of the body and velocity of centre of mass product as state above.Hence now we can write 

→               →  →  →                            →

Psystem  = p₁+p₂+p₃+........................+pₙ

Hence total momentum of a body is equal to vector sum of momentum of individual particles.

                                                            

What is meaning of collision in physics

What is meaning of collision in Physics?

Collision is important and interesting topic of physics, If you have already studies previous post like centre of mass, conservation of momentum and your concept is clear then you will enjoy learning collision. We will study from basic concept of collision to depth concept of collision step by step in easiest way so that you can understand complete concept of collision, don't worry your all doubt and confusion will clear about collision and you will learn some new concept of collision in this post. If you don't know about conservation of momentum then i will suggest you to refer post conservation of momentum concept  so lets start collision.

What is meaning of collision in details?  

The meaning of collision in Physics is not like that two bodies collide together.The real meaning of collision is if any one body velocity effect the other body velocity or one body momentum effect other body momentum, it is not necessary to collide with other body but effect the momentum of other body is called collision. 

But in our syllabus all question will be based upon the collide cases in which the momentum will exchange.So collision is an event in which two bodies strike each other applying large force for a small time.

So all the story of collision will be based upon the momentum, Hence any kind of collision you will apply conservation of momentum to the system, Why system ? because a single body can not collide itself at least two body required so two body system.

Hence the initial momentum of two body will be same as final momentum of two body and will also be same in between initial and final position.

So momentum remains conserved throughout the collision 

We see example of collision in day to day life like when we drop a ball on the ground it reaches the ground and strike the ground then bounce back to some height. The time at which ball strike the ground that event is called collision see below picture.

                                                                 

Collision

    

                                                         

electromagnetic wave

Electromagnetic wave

Electromagnetic wave a special gift of nature, You will learn in this post, What is electromagnetic wave ? How electromagnetic wave is created ? Types of electromagnetic wave ? Application and uses of electromagnetic wave, How electromagnetic wave propagate in the space ? History and depth concept of electromagnetic wave, This is very important topic of Physics and really very interesting, I hope and ensure you will enjoy to learn electromagnetic wave, This will be long post but i will suggest you to read complete post, so that you will never forget about electromagnetic wave so lets start. 

Electromagnetic wave is special gift of nature

This world work on nature principle, Today you are able to talk 1000 km far distance with other peoples sitting in other countries, Even you can see them. You can go other country in few hours. You can get any information within second.

You can know and get information about planets, stars which are very very far distance from you with the help of science.You know from Physics concept nothing is at absolute rest or in absolute motion in this universe, always taken one body with reference to other object, So rest and motion is always relative, Now you will ask if Earth is moving then why not my home location change ? your home always find at a fixed location this is because you and earth are in same reference frame, in more details i want to say your home location is not changing with respect to surrounding  so you feel your home is at rest and is fixed at a point but if you will see from the Sun then you will find your home location is changing due to the Earth rotation.

For more details about relative motion your can refer the previous post Relative motion concept, When reference is change then speed of object is change but this is not valid with light speed it does not depend upon reference frame and light is an electromagnetic wave. 

                                                                       

Electromagnetic wave

                                                                                 

acceleration due to gravity

Acceleration due to gravity

Today post is all about acceleration due to gravity, In this post you will learn, what is acceleration due to gravity ? How its value is 9.8 m/s², acceleration due to gravity has fixed value, Why and how its value varies at different point location and due to Earth rotation, How acceleration due to gravity is a gravitational field, You will learn all concepts about of acceleration due to gravity, so lets start.

What is acceleration due to gravity ?  

Gravity is a force with which Earth attract every other object towards it centre. Earth has created this gravity around its surrounding. This property of the Earth is due to heavy mass of the Earth, Because compare to the Earth mass, all other objects masses are small near its surrounding, Hence all other masses falls towards centre of the Earth.

                                                               

Acceleration due to gravity

From the figure above Earth is pulling you with force mg, you also know from the law of gravitation force between two masses, you can refer previous post for Gravitational force  the value of force between Earth and man shown in figure will be F= GMₑm/(Rₑ + h)²

here value of h is very small compare to radius of Earth Rₑ so h is neglected,

Hence F =  GMₑm/Rₑ² , Now both force will be equal as per statement.

GMₑm/Rₑ²  = mg   or  g =    GMₑ/Rₑ² , this is important formula where G is universal gravitational constant G = 6.67x10⁻¹¹ Nm²/kg², Rₑ is radius of Earth approx Rₑ = 6400 km,

 Rₑ = 6.4x10⁶ m , Mₑ is mass of Earth approx Mₑ = 6x10²⁴ kg .

Now after putting all the values in above formula g =  6.67x10⁻¹¹x6x10²⁴/(6.4x10⁶)²

g  = 9.8 m/s², remember this value of g is near the earth surface only.

 Suppose if h is very high then you can't neglect value of h, so in this case g =  GMₑ/(Rₑ + h)², Now as the value of h increases then value of g will decreases, So you can't say value of g is constant.

On increasing the value of h from the surface of the Earth value of g will decrease. You will see how the value of g decreases as moving from the surface of the Earth in this post later.

Now see below picture and find weight.

                                                                   

Weight at Mars

                                                                          

gravitational field and intensity

Gravitational Field and Intensity

Today topic is gravitational field and its intensity, You will learn in this post, what is field and how this field is created and what is strength or intensity of this field. This is new concept of gravitation and interesting,In previous topic you have learned in details about Gravitational force, that concept of point mass will be also use here to understand better about gravitational field, so you can refer first Gravitational force introduction. Now lets start and learn some new concept for gravitational field.

Gravitational field and electric field are similar, Gravitational field concept will apply in electric filed. Only difference is that in gravitational field mass will be source of field but in electric field charge will be source of electric field.

Gravitational field is always attractive in nature but electric field attractive as well as repulsive depend upon charge nature positive and negative. you will learn latter about electric field, here you will learn best concept for gravitational field. 

Gravitational field

                                                                  

Gravitational field

 See the picture above, Suppose a room is completely vacant, now you released a very small mass then that mass automatically start to moves towards a particular direction as shown in picture.

Now you were start thinking how this mass is moving, so that nothing is pushing the mass but it is moving, the thing which is invisible but effect are showing mass is moving, Then i told you that there is an imaginary field, Someone has made this field due to which this small mass is pulling, After that you remove the screen and found that Oh, There is a big mass, Now you clearly think that definitely big mass is pulling the small mass by law of gravitation.  

Hence this big mass has created gravitational field. Since the big mass will not seen but its effect you seen this is the imaginary field. This is a hypothetical concept story imaginary field but in actual not like this happen.

                                                             

gravitational potential energy

Gravitational potential energy

Gravitational potential is very important concept because the same concept is used in electric potential, So potential is a general concept, Which you need to understand the concept behind potential. Whenever you see gravitational potential then you must remember, the existence of gravitational potential is due to mass.

If mass is not present then gravitational potential will not exist, Can you think why ? well if there is no mass then there is no gravitational field and if no gravitational field then there is no gravitational potential.

So you can think potential depends upon field, which may be gravitational field or electric field or magnetic field in general but here you will learn about gravitational field potential.

If you have not studies gravitational field then i will suggest you first to learn about gravitational field in my previous post so that you can better understand gravitational potential concept, You can refer link Gravitational field.

When you see electric potential this is due to charge, but the potential concept for both the cases is same. Hence you will learn in this topic, what is potential ? and how it is calculated, why need to learn potential ? and then potential energy.   

What is gravitational potential ? 

Potential word itself has not got any defined meaning, whereas potential difference is defined as "the difference in potential between two points that represents the work involved or the energy released in the transfer of unit quantity of mass from one location to the other location". So it is clear that potential is a characteristics of location or point.

Suppose there are two points A and B and a small mass m is kept at point B, now this small mass m bringing from point B to A, now you need to do some amount of work that amount of work is called potential difference between B to A.

                                                                                                                                  ←m

Mathematically written as  Va - Vb  = (Work done B to A)/m             A         W            B  

with no change in kinetic energy, means when you are bringing mass m from point B to A the speed of mass does not change during the journey from B to A.then only this formula is valid.

Potential at a point 

As i have stated potential itself is not a defined meaning in Physics, So we have taken a reference point, such that the potential of reference point will be zero. Now you can compare any new point potential from that reference point, like how much is potential at new point.   

Hence reference point was take at infinity (∞) so potential at infinity is zero, now you are able the compare any new point potential respect to infinity potential. But remember point does not have energy but whenever you bring a mass near to that point then energy is stored in mass.

So it is clear that energy is available in mass but potential at point or at location indicate how much energy will be available at that location in the body or mass, which is bring to that point. You must remember every point has some potential, If you bring a mass then energy is stored in mass, If you don't bring the mass then energy is not stored, but potential is always there.

You generally listen the peoples use potential word like, there is potential in this business, what do you understand by using this word ? Well that person is indicating about money in that business, Hence money is form of energy in Physics.
So potential indicate about energy of at point or location but when you bring a mass.         

Now from the above two point, which you have taken A and B put point B at infinity that is B(∞), now put a small mass m at infinity and bring this mass to point A, the work done will give you the potential at point A.

Now you can write mathematically  VA - V∞  = (Work done infinity to A)/m  put V∞ = 0 then you will get  VA  =  (Work done W infinity to A)/m .

what is VA ?  this is potential at point A.

Actually potential at a point does not exist, we are just comparing from infinity point potential so you are able to define potential at point A.

Hence potential at a point is define as work done per unit mass bringing  from infinity to that point A, such that without changing the kinetic energy of mass m means mass moving very very slowly from infinity to point A.

Now i hope your concept about potential and potential difference is clear.

Gravitational potential due to a mass M

                                                                 

Gravitational potential