Law's of Resistance

Law's of Resistance
The resistance of a wire depends upon its length, area or cross section, type of material, purity and hardness of material of which it is made of and the operating temperature.

Resistance of wire is
> Directly proportional to its length
> Inversely proportional to its cross section.

Ohm's Law

Ohm's Law
The current flowing through a conductor is directly proportional to the potential difference across the ends of the conductor and inversely proportional to the conductor resistance. 

Ohm

Ohm
Ohm is defined as the resistance between two points of a conductor when a potential difference of one volt , applied between these points, produces in this conductor a current of one Ampere.

Resistance

Resistance
Resistance is the property of a substance which opposes the flow of electric current passing through it.
Unit:- Ohm

Volt

Volt
Volt is a unit of electromotive force as well as potential difference .

Volt is defined as that potential difference between two points of a conductor carrying a current of one ampere when the power dissipated between these points equal to one Watt.

Potential Difference

Potential Difference
Potential difference between two points in an electric circuit is that difference in their electrical state which tends to cause flow of electric current between them..

Unit of Potential Difference:- Volt

ElectroMotive Force (EMF)

Electromotive Force (EMF)
EMF is the force that causes an electric current to flow in an electric circuit.

Unit of Emf -- Volt

Electric Current

Electric Current
The controlled movement of electrons through a substance .
or
The time rate of net motion of an electric charge across a cross sectional boundary.

Electric current is specified as -- Ampere or Coulomb per sec

Function Queue

Function Queue
A queue of pointers for the function awaiting later execution.

Data structure

Data structure
A multi-element structure that can be referenced by a common name (identity).

Data Type

Data Type
Type of data for variable .
Example:- An integer.

Header File

Header File
File containing codes ( mostly standard functions) for the user.
Example:- a file "math.h" containing for the mathematical functions.

Include File

Include File
File that is included along with the user source code before the compilation by the compiler.

Preprocessor Directives

Preprocessor Directives
Program statements and directives for the compiler before the main function to define global variable , global macro (section of code) , new data type and global constants.

Platform Independance

Platform Independance
A code that can port on different machines and operating systems.

Portable

Portable
A code that can be ported in another program by suitable configuration changes. 

Robustness

Robustness
A program is said to be robust if it can function without errors like stack overflow and out of memory errors. Avoiding pointer manipulation instructions, frequently freeing the memory if not needed later and using exceptions, make a code robust.

Modularity

Modularity
A set of codes are said to be modular if they are usable in the multiple applications.

Class Libraries

Class Libraries
Classes for a number of application like encryption m security, may be provided after thorough debugging and testing for using these in the requirements. Use of class libraries speed up program development cycles.

Foundation Classes

Foundation Classes
Classes meant for GUI's (graphic user interfaces, for examples, the button check box , menu, etc).

IO stream

IO stream
A memory buffer created by sending the bytes of characters from a source to a destination so that the destination acts as a sink and accepts them in a sequence that they are sent. An IO stream object does the writing to a file or printer or to a queue or to a network device.

Virtual Base Classes

Virtual Base Classes
A special type of classes provided in C++.

Exception Handing

Exception Handing
A way of calling the function on handle development of an exceptional condition.
Example:-
Buffer unable to store any further byte. A programmer thinks of the exceptional conditions and provides for the functions and their calling on occurrence of the exception.

Multiple Inheritance

Multiple Inheritance
A daughter (derived class) inheriting the member functions from more than one class. 

Template

Template
A set of classes using which new classes are built.

Runtime Library

Runtime Library 
A library function that links dynamically at the run time. Run time links increase run-time overheads and out of memory errors can arise. 

Runtime overhead

Runtime overhead
Use of RAM for data and stack is called run-time overhead.

NULL

NULL
When a pointer points to NULL, it means there is no reference to the memory. A memory occupied by an element or object or data structure can be freed by pointing it to the NULL.

Local variable

Local variable
A variable defined within a function , and which no other function can modify. 

Reference Data Types

Reference Data Types
Array and strings are examples of reference data type.

Private

Private
A variable belonging to a specific class and not usable outside that class. 

Scalar Data Types

Scalar Data Types
The character, integer, unsigned integer, floating point numbers, long and double are called scalar data type, Unlike an array, data consist of one single element.