What is Charge, current, voltage? Definition explanation

Charge

Definition:

“Charge or Electrical charge is the property of, unit of a matter”

Explanation:

Charge does not physically exist; this is only a theoretical word. Yes, we use the word charge physically in many topics, just to describe the topic by taking a simple or basic thing (charge). Charge tells that how the matter will react with the other matter or in a magnetic field or in a electric field.

A matter is named as charge, only when there is a difference in number of electrons and number of protons in atom of that matter. If there are more electrons than proton in atom then it is negative charge and if there are more protons than electrons then it is positive charge. Hence this is two types of charge negative and positive charge.

Unit:-

The unit of charge is Coulomb and represented by q. 

Current

Definition:-

“Current is the rate of flow of electric charges.”

Explanation:-

Current is the flow of electric charges which is free electrons. Current flows in a circuit when there is pressure or some force applied to the charges in a circuit. Current flows from negative end to towards positive end. Rate of flow means, how much charges will flow in some fix time. There are two types of current. AC and DC.

AC means alternating current. The current which changes its direction of flow after half interval is known as alternating current.

DC means direct current. The current which flow in only one direction is known as DC current.

Each type of current has its own application.

Unit:-

Unit of current is A Ampere.

“When one coulomb charge will flow in one second through some point, then current will be one ampere.”

 Voltage

Definition:-

“Voltage is a force or pressure which causes the charges to flow through circuit.”

Explanation:

As we discuss in explanation section of current that , current flows through the circuit when some force or pressure applied to the charges in circuit. That force and pressure is Voltage. It is also known as potential difference. In some words, Voltage is the power of current. Means with how much power the current is flowing. The more the voltages the more the rate of flow of current in a circuit.

Unit:

Unit of voltage is V volt.

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!

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,

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.

Electric Charge density, definition, explanation

Definition:

"Electric charge density is the amount of charge on unit volume space or surface or area."

Explanation:

Electric charge density is the density of charge on unit area, the charge could be less or  more, and charge could be positive or negative.
as shown in figure 1 below, in which there is positive charge on surface but less and on figure 2, there is more positive charge.

So area in figure 2 have more electric charge density than figure 1.

The area or volume could be one dimensional, two dimensional and three dimensional. 

Formula:

The electric charge density can be written in the form,

Where p is the charge density and q is the amount of charge and v is the volume of space and unit area. we can replace the v by A, when there is unit area.

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.)

Capacitive and Inductive Reactance and their explanation

Capacitive Reactance:-

"Capacitive reactance is the resistance offer by capacitor to the current."

Explanation:-

Whenever there is current flows through the capacitor there is the opposition offer by it to the current, which causes delay in its charging. And its this reactance depends upon the frequency of AC current flowing through it. the more the frequency the less its reactance will be and less the frequency the more the reactance will be. The formula for the capacitive reactance is below.

Inductive Reactance:-

"Inductive reactance is the resistance offer by inductor to the current flowing through it."

Explanation:-

When AC current flows through the inductor it offer some resistance to the current. it depends upon the frequency of current. The more the frequency the more the reactance and less the frequency less the reactance. This behaviour is of inductor when AC current flows through it.

Inductor, Inductance, explanation, formula

Definition:-

"Inductor is an electronic device that is use to store energy in the form of magnetic field."

Explanation:-

Inductor store energy in magnetic field around it. Inductor is an coil of a conductor(wire). wire wounding on some rod or magnet. when a current passes through the conductor then there will be magnetic field around the wire. We wound the wire because by winding there would produce a strong magnetic field around this, we could increase the strength of  magnetic field around coil by taking efficient core like magnet and by increasing number of turns of coil and increasing cross sectional area of inductor. When current flows through the inductor there would produce magnetic field around it and in that magnetic field energy would be store (in the form electrons). It would be store until current is flowing through it. When current will stop it will release all the energy.

Inductor does not allow AC current to flow through it due its changing direction nature. While inductor resist to change in current so it becomes open in a circuit while AC current flows through the circuit. It allows DC current to flow through it. After charging completely it allows DC to flow through the circuit hence become short in circuit with zero resistance.

Inductance:-

Inductance is the property of a inductor which is that "whenever Flux is changed in it, it produces an EMF."

or in simple words

Inductance is the ability of an inductor to store energy in the form magnetic field.

Henry is the unit of Inductance.

Formula:

formula for inductance of inductor is,

Electric Fields lines and Forces

Electric Fields:-

"Electric Fields are the area or space or region around a body or particle which is charged, in which area it effects(attracts or repel) on other body or particle which is charged."

Explanation:-

Consider their is a charged particle A, it has Electric fields lines, because it is charged. When a unit positive charge(small charge) will come into its field lines then it will feel some force, which is the effect of Charged particle A. It will repel the unit charge (as positive and positive repel each other).

The unit positive charge will only feel this force when it will come into the region where there is Electric field lines of Particle A.

In above diagram unit charge 1 will feel force as it is in the field region of charged particle A, but 2 will not feel any force as it is out of field lines of charged particle A. 

Electric Forces:-

"The force which charged unit positive charge feel when it is in the electric field lines of charged particle (A)."

Explanation:-

As Charged particle have electric field region where it exerts some force on some other charged particle (when it comes in the electric field of that charge). There are two type of forces which is exert by the charged particle in its field region. Attractive force and Repulsive force. Positive charge exert repulsive force on other positive charged while it exert attractive force on negative charge. In general there is attractive forces in opposite charges and there is repulsive force in between like charges.  

In below pic A is positive charge and it is repelling other positive charge.

In below pic, A is positive charge which is attracting negative charge.

Equations of Motion(and their derivation)

There are three equations of motion:-

Explanation:-

This equation is used to find the final velocity of a body or latest velocity of body or current velocity of body. This equation is known ass first equation of body.
Whenever a body starts to move it have some initial velocity and when after some interval of time t it have some change in velocity, after which its velocity becomes So above equation is for final velocity. Now see its derivation.
Change in velocity ∆v is equal to,

(2)

This is equation is used to find the distance covered by a body having initial velocity Vi and after time t.

Consider a car moving with initial velocity Vi and final velocity Vf, then it would have average velocity will be,

 

(3)

In this equation there is distance , acceleration, final velocity and initial velocity are related.

We could find one, if we know other.

According to first equation of motion,

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

Transformer, Definition, Explanation, working, construction, types

Definition:-

"Transformer is an electrical device that converts low voltage into high voltage or high voltage into low voltage."

Explanation:-

Transform the current or voltage, it is used to get high voltage when input is of low voltage and to get low voltage from high voltage.

Transform works on the principal of Mutual Induction, according to which "When alternating current flows through one winding of coil, due changing nature of ac current, there produce an emf across winding and magnetic flux around winding. When another winding of coil comes near the first winding, there is effect of magnetic flux of first winding on second winding and due to AC current as it changes continuously produces changing magnetic flux of first winding and due to this change there causes the EMF in second winding and hence current starts to flow through second winding, so this process is known as mutual Inductance". Transformer works on this principle. As there is no connection between two coils(we just bring the second nearer to the first), the current transfer will be very small as compared to first. So we use Core to link these two winding, because of this current loss is so small.

Construction:-

 It consists of following,

1.Primary coil

2.Secondary coil

3.Core

4.AC current source

Working:-

Whenever we supplies ac current to primary coil then due to changing nature of ac current there produces change in magnetic flux around this winding. And due to this changing current starts to flow through core and reached to the secondary winding and through this secondary winding goes to external circuit, When we need to change low voltage to high voltage then we have to increase the winding of secondary coil. This type of transformer is known as Step up Transformer. If we want to change the high voltage into low voltage, than we have to decrease the winding of secondary coil. This type of transformer is known as Step down Transformer.

AC Generator

Definition:-

"The machine which is used to convert mechanical energy into electrical energy(AC current) is known as AC Generator"

Explanation:-

The device which gives us AC current(Electrical energy) by taking mechanical energy from any source(could be us) is known as Ac generator. Its construction is similar to dc generator and its working is also same almost. 

The above shown diagram is of AC generator. our need is to get the current which changes its direction after every half cycle, so to get this we need to get the current from one slip ring for one half and for other slip ring for the second half. Slip rings are connected at different ends of closed circuit. where load is connected. So that load will get Ac current.

Construction:-

It consists of following parts:-

1.Magnet

2.Slip Rings or Commutator

3.Conducting Coil or Armature

4.Carbon brushes

5. Load  

Working:-

According to the Faraday's Law of electromagnetic induction, whenever a conducting coil is move or rotates across magnetic field emf produces in it and due to this, current starts to flow through it. So in this generator when coil will move by some mechanical force across magnetic field of magnet, then there will produce an EMF and because of this, current will start to flow through it(if coil path is closed or connected to other circuit). Direction of current will be according to Fleming's right hand rule. 

As shown in this diagram, For first half rotation of coil the current will go to the load form one slip ring and for 2nd half rotation of coil the current will go from the other slip rings to the load so it is giving ac current to the load as it is changing its direction after every half cycle.

Generator(DC)

Definition:-

"The device which converts mechanical energy into electrical energy is known as Generator."

Explanation:-

Generator use to produce electrical energy from mechanical energy for our purpose.

Above shown diagram is of DC generator, its construction is same as Electric motor(DC), the difference is that from where we give input in input, from there we get output from generator. the mechanical energy could of any type. for example moving pivot with your hand and by some other source.

Construction:-

It consists of:-

1.Magnet

2.Conducting Coil loop

3.Commutator

4.Carbon brushes

5.Battery

Working:-

According to Faraday's law, whenever a conducting coil will move across magnetic field then there will produce an EMF, and due to this, current will start to flow through coil (if path is closed). the direction of current will be according to Fleming's Right hand rule(Described below). Then this current will go through commutator and through carbon brushes it will go through battery and will charge. That its simple working!

Faraday's Law of electromagnetic induction:-

This law state's that" whenever a conducting coil is move across the magnetic field of magnet, then EMF will produce in coil and current will start to flow through it" Current direction would be according to Fleming right hand rule.

Fleming's Right hand rule:-

According to this law "Straighten your thumb, fore finger and middle finger so that they become perpendicular to each other(right angle to each other) and then your thumb will represent the coil, your fore finger will represent the magnetic field and your middle finger will represent the direction of current flow."

Electrical Motor(DC)

Definition:

"Electric motor is a device that converts electrical energy to mechanical energy"
The device which converts electrical energy into other form of energy which is mechanical energy so that we can take benefit from it.

Types of Motor:

There are two basic types of electric motor:-

1.DC motor

2.AC motor

 

DC motor Explanation:

The motor which converts DC power to the mechanical energy or power is known as dc motor.

Above diagram is of dc motor. It consists of a magnet, armature or conducting loops, carbon brushes, commutator, dc source or battery.

Working:-

When we connect the battery with the carbon brushes than through commutator they cause the current to flow through loops, as on the other hand there is also magnetic field from north to south so as we have studied Fleming's left hand rule(will explain below), the loops will move upward from one side and will move downward from other side. When this current carrying conductor(conducting loops) will change position at 90 degree than again according to the Fleming's rule this loop will move as it is going. So that how it works. other end of loop would be connected with the object to whom we want to provide mechanical energy. 

Fleming's Left hand rule:-

This rule states that" hold your left hand and tied your 1st finger, 2nd finger and thumb in such a way that they each other become perpendicular(Right angle) to each other. now if first finger is the direction of magnetic field and 2nd finger represent the current flowing through coil, then thumb will represent the force acting on it." 

What is Force?

Definition:-

"Force is a reason or something that causes the change in a motion or situation of a body."

Explanation:

Force is the reason which causes change, if you want to move something or you want to do some work you have to apply force.
A force is a vector quantity. a vector quantity is a quantity that has both magnitude and direction.




Unit:

Force is a quantity that is measured using the standard metric unit known as the Newton.  
1 Newton = 1 kg • m/s2

Formula:

According to the newton second law of motion, force is the product of mass and acceleration. Means force depends on mass and acceleration of body.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.
F=m.a

What is motion? Types of motion

Motion:-

When a body does not change its position with time it is said that it is in rest but when it changes it is called that body is in motion.

Types of Motion:-

There are few basic types of motion:

1. Translational motion

2. Rotational motion

3. Random motion

4. Circular motion

Translational:-

A body covering some distance while moving whether it is on straight line or curved line, but distance covering is necessary. it is known as translational motion.

i.e. You driving a car towards your destination the road sometimes will not be straight turns will come but you will cover distance.

Rotational:-

A body moving on its axis and its all parts have different directions. no matter in which direction it moves but move on its axis is known as rotational motion.

i.e. A beblayde moving on its axis, a fan blades moving.

Random Motion:

When a body moves randomly, it is known as random motion.
Random motion means when body doesn't follow a specific path just a zig zag type path to move then this movement is known as random motion.

i.e. Fly, Mosquitoes etc,  flying around you randomly is an example of random motion.

Circular Motion:

When a body moves in a circular path, it is known as circular motion.

it is simple type of motion when body moves in a closed circular path it is known as circular motion.

i.e. a racing car moving on a circular racing track.