Difference between Charge, Voltage & Currrent

Electrical Charge

Electrical charge is a fundamental quantity and is intrinsic property of matter which causes a force to act between particles (objects, bodies..) which have this property. It is physical quantity which can be transferred from one object to another.

Electric charge comes in two types, which wechoose to call positive charge and negative charge.

Electric charge can be measured using the law for the forces between charges (Coulomb’s Law). Charge is a scalar and is measured in coulombs. The coulomb is actually defined in terms of electric current (the flow of electrons), which is measured in amperes; when the current in a wire is 1 ampere, the amount of charge that flows past a given point in the wire in 1 second is 1 coulomb. Thus,

 

when charges are transferred by simple interactions (i.e. rubbing), it is a negative charge which is transferred, and this charge is in the form of the fundamental particles called electrons. The charge of an electron(e) is -1.6022 × 10-19 C.

The particles found in nature all have charges which are integral multiples of the elementary charge e:

 q = ne where n = 0, ±1, ±2 . . .. Because of this, we say that charge is quantized.

A charged object is an object that has an excess of one type of charge, e.g., more positive than negative. The amount of excess charge is the charge we assign to that object.

 

Current

Flow of charge moving through unit area in unit time. It represents charge transfer.

Voltage/Potential Difference

Voltage is a measure of the energy carried by the current. Technically it is a measure of the difference in energy between two points – hence the name potential difference. Voltage represents potential difference between two points. It represents work to be done to move unit charge from one point to other under influence of electric field.

 

WHAT IS CRYSTAL STRUCTURE?

Matter exists in three states viz. solids, liquids and  gases.  All these states are composed of atoms and molecules.  In case of solids, they are classified into many types based on several properties like  electrical, mechanical, magnetic, optical, thermal  etc.  The main reason for these different properties of solids is their crystal structure.

 Crystal Structure

 Periodic arrangement of atoms/ions over large atomic distances. Leads to structure displaying  LONG-RANGE ORDER that is Measurable and Quantifiable.

CRYSTAL

It is a substance in which the constituent particles are arranged in a systematic geometrical pattern.

SPACE LATTICE OR CRYSTAL LATTICE

A lattice is a regular and periodic arrangement of points in three dimension.  It is defined as an infinite array of points in three dimension in which every point has surroundings identical to that of every other point in the array.  The Space lattice is otherwise called the Crystal lattice.

Consider the points P, Q and R.

Let us join the points P and Q by a straight line, and the point P and R by another straight line.

The line PQ is taken as X-axis and the line PR is taken as Y-axis.

The distance between any two successive lattice points in the X-direction is taken as `a’.

Similarly, the distance between any two successive lattice points along the Y-direction is taken as `b’.

Here a and b are said to be lattice translational vectors. Consider a square lattice in which a = b.

  

Consider two sets of points A, B, C, D, E, F and A', B', C', D', E', F'. In these two sets, the surrounding environment looks symmetrical; i.e. the distances AB and A'B', AC and A'C', AD and A'D', AE and A'E' and AF and A'F' are equal.

WHAT IS BINDING ENERGY OF NUCLEUS?

The binding energy that holds nuclei together “shows up” as “missing” mass.

Deuterium is an isotope of hydrogen which contains a neutron, a proton, and an “orbiting” electron.

mass of hydrogen             1.0078 u

mass of neutron                1.0087 u

sum                                   2.0165 u

mass of deuterium            2.0141 u

difference                         0.0024 u

Since 1 u of mass has an energy equivalent of 931 MeV, the missing mass is equal to 931x0.0024 MeV = 2.2 MeV.

The fact that this mass deficit is the binding energy is demonstrated by experiments which show that it takes 2.2 MeV of energy to split a deuterium into a neutron and a proton.

Nuclear binding energies range from 2.2 MeV for deuterium to 1640 MeV for bismuth-209.

These binding energies are enormous; millions of times greater than even the energies given off in highly energetic chemical reactions.

We usually talk in terms of binding energy per nucleon, which is 2.2/2=1.1 MeV per nucleon for deuterium, or 1640/209=7.8 MeV per nucleon for bismuth-209.

The figure below shows a plot of binding energy per nucleon as a function of mass number.