Electric Charge


Electric charge       
Charge is an electrical property of the atomic particles of which matter consists, measured in coulombs (C).

The law of conservation of charge states that charge can neither be created nor destroyed, only transferred. Thus the algebraic sum of the electric charges in a system does not change.

Every matter in this universe is made of atoms. The atoms consists of proton and electron and hence they are electrically neutral. This is because, each atom has equal number of protons and electrons. Protons have positive charge. In an atom, protons are strongly bounded in the nucleus. So, protons cannot be detached from the nucleus by any normal process. . Electrons have negative charge. Each electron revolves round the nucleus in definite orbit in the atom. 

The quantity of electric charge of an electron is exactly equal to that of a proton but in opposite in nature.

The electrons which are farthest from the nucleus may be detached by any means. If some of these detachable electrons of neutral atoms of a body, are removed, there will be a deficit of electrons in the body. After, removal of some of the  electrons, the total number of protons in the body becomes more than total number of electrons in the body. As a result the body will become positively charged.

So, deficit or excess of electrons in a body of matter is called electric charge.

Charge of an electron is very small and it is equal to  -1.6* 10^-19
So, total number of electrons have electric charge of 1 Coulomb. So, if a body deficits 6.28*10^19 number of excess electrons, the body will be of 1 coulomb negative electric charge. 
On the other hand, if a body  has excess electrons, the body will be of 1 coulomb negative electric charge.


Comments

Post a Comment

Popular posts from this blog

Equivalent Ckt of transformer

Image
Equivalent circuit of no load transformer equivalent circuit  In the given figure we take primary referred equivalent. I 2 ’ = I 2 \a                       where,          a = turn ratio = N 1 \N 2 R 2 ’ = a 2 R 2                                    Gi = R 0        B m = X 0 X 2 ’= a 2 X 2 V 2 ’ = aV 2                     approximation circuit Full load equivalent phasor diagram for inductive load. The KVL equations for the primary and secondary circuits are V 1 = E 1 + I 1 R 1 + j I 1 X 1 V 2 = E 2 - I 2 R 2 - j I 2 X 2 ...
Read more

No load equivalent circuit

Image
No load equivalent circuit The primary winding draws a small amount of alternating current of instantaneous value I o , called the exciting current , from the voltage source. The exciting current establishes flux f in the core. When the primary side is connected to sinusoidal voltage source V 1 a current known magnetizing current I m flows in it. This current set up a alternating flux in the core. Hence it is called a magnetizing current. The flux Φ m is proportional to I m . I m lags behind the applied voltage v 1 by 90.    The flux Φ m links with both the primary and the secondary winding. When it links with primary winding it produce self induce EMF E 1 which is opposite to applied voltage. Similarly alternating flux links with secondary side its produce mutually induced EMF E 2 . Both E 1 and E 2 lag behind the Φ by 90 degree. This can be shown by the phasor diagram. Here the losses are neglected. No load equivale...
Read more

NPN transistor

Image
The most commonly used transistor configuration is the  NPN Transistor . In this, we used common emitter configuration of NPN Transistors. The transistor has three regions, namely ; emitter, base and collector. The base is much thinner than the emitter while collector is wider than both as shown. However, for the  sake of convenience, it is customary to show emitter and collector to be of equal size. The emitter is heavily doped so that it can inject a large number of charge carriers (electrons or holes) into the base.  The base is lightly doped and very thin ; it passes most of the emitter injected charge carriers to the collector. The collector is moderately doped The resistance of emitter diode (forward biased) is very small as compared to collector  diode (reverse biased).  Therefore, forward bias applied to the emitter diode is generally very small  whereas reverse bias on the collector diode is much higher.    ...
Read more