Electricity is Magic

 Have you ever wonder why do we sometimes feel a spark of electricity or when we touch a metal? or ever thought when we turn of the light and stand infront of a mirror then what the that light that comes when we take off the shirt(specially in winter when air is dry). 

All these happens due to presence of static electricity in ours or others body.

Then what is electric current or static Current?

firstly, Current is defined as the flow of the material, it can be any thing: water or may be electrons.so electric current is defined as the flow of the electrons in a conducting material. so we know if we can move electrons from one end to another we can produce electricity. so if we take a material in which free is present(conducting material) and create a certain of force then we can move electron. so which force can do that? then here it comes magnetic field force.

if  we can somehow make the magnetic field acts on the electrons continously then flowing of electron can be possible. so what can make that happen?

Changes the magnetic field in the electrons can easily make the electrons to move(current).

if we take a piece of a conductor then place it in a continous magnetic field then the electrons can move and that will form a electric current in the conductor and this phenomenon is known as electromagnetic induction and discovered by Michael faraday in 1831. 

Dynamo, Motor and other spining of vibrating electrical instrument is based on electromagnetic induction.

In most of the cases if  the device can move giving electrical energy then moving the device can produce electric current too. This is how elecitrial devices works: For a motor two fixed magnets are placed in a placed one facing north and another facing south now magnetic field will go from north to south. if we place a wire in that field then its our setup.

Fleming's Right-Hand Rule was discovered by British engineer John Ambrose Fleming in 1890 to explain the direction of induced current when a conductor moves through a magnetic field. According to this rule, if you stretch the thumb, forefinger, and middle finger of your right hand so they are mutually perpendicular, then the thumb represents the direction of the motion of the conductor, the forefinger represents the direction of the magnetic field (from North to South), and the middle finger shows the direction of the induced current. This rule is mainly applied in electric generators to determine the direction of the current produced by electromagnetic induction.

Now, when the two of the following is completed then one will form in the given like:

➤When we suppy current in the present magnetic field then the force will act in the wire like from fleming right hand rule. motor rotates due to this phenomenon.

➤when we apply force in a presence magnetic field then some EMF(electro motive force-the maximum voltage produced by a source when no current is flowing)will be produce in the wire. Dynamo and generator are examples of it.

that's why we can also produce electricity with the help of motor.

Differences between voltage and emf :

Have you ever thought about what are the types of types of current? What are the factors that may differentiate its types? and why do we need different types of current?

There are two types of current AC(alternating current) as we know with its name, its frequency moves in alternating condition like a Sine wave. we sometimes listen the frequency of Nepal current is 50hz but frequency of USA is 60hz so what does it mean? it means the frequency of the current will change 50 or 60 times in a second or we can suppose that the current will on/off 50 of 60 times in a Second.

so, why does we know lights going off and on? that's because 50 or 60 times a second is a very small duration of time and our eyes can't capture it. that's the reason in some camera we may see lights getting on and off but its rare in modern bulb there are capacitors to avoid that thing.we have another type of current which is DC(Direct Current) direct current doesn't have any thing like changing frequency so it have zero frequency we have used DC current in simple circuits.

AC have its property that it can change its voltage with the help of transformer so we use AC to transfer current from station to household.

here is why is this and how its works: when electricity travel from one point to another its flow is tried to stop by resistivity of the material(resistance: the property of a material or component that opposes the flow of electric current.) so flow is reduces and we need to increase flow so which thing can do this? now here comes the transformer, transformer helps to increase the flow of the current. and due to this the loss in current while transmitting electricity is reduce.

Conclusion: DC can't  change its voltage so we use AC to transfer electricity from power house to house where trasnformer plays a vital role but we use DC in most of the cases to operate device in which AC is changed to DC by rectifer and DC is change to AC by Inveter.

You probably heard the word "transformer" before do you know what's that or why is that use for?

Transformer is a electrical device that can change the voltage of AC. 

Transformer works on principle of Electro-magnetic Induction lets observe the structure of transformer.

the above picture is a outer part of a transformer