Sunday, June 29, 2014

Ohm's Law 


As the our discussion continues, the last topic we have tackle is the Ohm's Law which named from George Simon Ohm. This lesson applies the topic we have learned in Physics 2 which is Kirchhoff Law which is presented this kind of example.

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The Ohm's States that: 

The Voltage V across a resistor is directly proportional to the current i flowing through the resistor 


Simple Application :

The application of ohms law in a very simple example is that ... when you push a heavy material, you will have to exert a force in order to move the material, but when the material is heavier that you'd expect, you exert more power to push the material. As sir Jay Villan our teacher explain. 
Upon the observation, the force exerted by a person that causes the table to move is the voltage , and the motion or the movement that is causes to move is the current (i), and the material which is heavier is the resistance which the person need more power to push the material.

Ohm's Law Formula 


the formula for the ohm's law is came from the formula V = IR which you can derive. If you will find the voltage you will use V=IR, and if you will find the current the formula will be I=V/R. And if you will find the resistance the formula will be R=V/I which the answer will be measured in Ohms. Which states that "The resistance R of an element denotes its ability to resist the flow of the electric current, it is measured in ohms".


Sir jay also discuss the flow of a circuit which i think on my understanding, there are two types , a SHORT circuit and a OPEN circuit.


Short Circuit:
A short circuit defines that a circuit element with resistance approaches to zero.


Open Circuit:
A open circuit is circuit element resistance approaching infinity which means that there is no current flowing through because of its open circuit.

TYPES OF RESISTOR
A resistor is either fixed or variable. Most resistor are of the fixed type, which means their resistance remains constant. the two common types of fixed resistors are WIREWOUND and COMPOSITION. The composition resistors are used when large resistance is needed. A common variable resistor resistor is known as a "potentiometer",it has three-terminal element with a sliding contact or wiper in which the resistance vary of changed. 

example:







Conductance

       Conductance is the ability of an element to conduct electric current; it is measured in mhos or siemens.

A useful quantity in circuit analysis is the reciprocal of resistance R, known as conductance and denoted by G:


G=I/R=i/V


Resistor Color Coding:


Resistor color code chart




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