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Current | Voltage | Resistance | Terms definition and knowledge | Electrical Fundamentals

 Hello friends , we are here to learn current, voltage, and resistance. All three are the basic things needed for understanding the concept of electricity, electrical networks, and developing more knowledge . so let's learn together,



Q. what is current?

ans. In simple, you can say that flow of electrons or charge is called current.

                                                         or

• At the standard level you can say that the rate of change of charge is called current. In any conductor when you apply some voltage (or) potential difference across the conductor, conductors have some electrons so that electrons start moving. So current starts flowing through that conductor.

* It is denoted by capital I. 

* current is measured in Ampere. (charge/second)


formula : I=dq/dt 

∆ where dq/dt= rate of change of charge/electron concerning time.


let's do an example for understanding it properly

Consider,,

The number of electron flowing conductor is 6 and the time is 10 sec. calculate the current through the conductor?

ans:  dq= 6 , dt=10 sec. current (I)=6/10=0.6 joule/sec.(ampere)

hope this example helps you to understand very well not so hard just go with ease

Note:-

current is flowing through the conductor, not across the conductor.


Q. What is voltage or potential difference or electromagnetic force?

ans: The force which pushes the electron to flow in simple ways.

                                                     (or)

In standard or books language 

Definition: It is the pressure or potential energy of charges of two points in a circuit. if one point has more no. of negative/positive charge we say that it has higher potential and while 2nd point has lower potential.

* it is denoted by voltage ( capital V for fixed voltage value and small v for variable voltage .)

* Voltage or potential difference is measured in (unit)  volts or joule/charge.


formula : V= dw/dq (volts)

              where,

                          dw/dq= rate of change of work done with respect to charge.  

                          * V= voltage 

                           *dw= work done 

                            *dq= charge 

Note:-

•voltage is force or pressure that causes the current flowing in any conductor.




Q. What is Resistance?

Ans. Simple words say that any obstacles/material which opposes electron to flow. 

         •its unit is ohm. ( Kilo, mega ohm for high resistance values)


∆ Resistance depends on the following factors

• made of Material  of conductor

• Temperature 

• crossectional  area of the conductor

• length of the conductor

                 •  R~length

               •    R~1/crossectional area 

                 •  R~tempreature 


R= resistivity × length /crossectional area



One law will relate all these three things

Ohm's law:- according to this law, the potential difference across the conductor is directly proportional to the current flowing through the conductor.

        • V~I 

       •  V=RI

You can also have the units of each quantity from this formula. 

Q. Current (I) = 10 amp , and resistance (R) = 2 ohm . Find out Voltage (V) = ?   

Notes:-

✓Resistance is measured by megger.

✓Current is measured by Ammeter. (current meter)

✓Voltage is measured by a voltmeter.

( आपको बहेतर रूप से समझने के लिए प्रयोग किया गया इमेज है |  ) 



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