♦ Resistance - Ohm's Law ♦

    Resistance is defined as the ability of a substance to prevent or resist the flow of electrical current. We can calculate resistance by measuring the quantities of potential difference across the load and the current passing through it.            


                                    R = V / I            

R is measured in ohms, named after Georg Simon Ohm (1787-1854)
    Mr Ohm found out that the V / I ratio was constant for a particular resistor, and that was the first step in the development of Ohm's Law. 
There are 4 factors that affect Resistance:
          ◘ Length - If the length doubles, so does the resistance.          ◘ Cross-selection area - it the cross-selection is doubled, then the resistance is cut in half.          ◘ Type of material - Since some materials are better than others, if the resistivity (general measure of the resistance of a substance) is doubled, then the resistance is also doubled.           ◘ Temperature - (This only occurs is some substances) If the temperature of the conductor is increased, it usually leads to an increase in the resistance. 
   ○ Kirchhoff's current law states that the total amount of current into a junction point of a circuit equals the total current that flows out of that same junction.     ○ Kirchhoff's voltage law states that the total of all electrical potential decreases in any complete circuit loop is equal to any potential increases in that circuit loop.