PlanPlan

• What is a What is a resistorresistor??

• How can we measure the How can we measure the resistanceresistance??

• Ohm s Ohm s LawLaw..

• Types of Types of resistorsresistors..

• Parallel connection.Parallel connection.

• Series connection.Series connection.

ResistorsResistors

• George Simon OhmGeorge Simon Ohm

What is a resistor?What is a resistor?

• Opposes the path of electrical Opposes the path of electrical current.current.

• Produce heat energy. Produce heat energy.

Ohmmeter is an instrument Ohmmeter is an instrument used to measure resistance.used to measure resistance.

Ohm s Law:Ohm s Law:

• Ohm's lawOhm's law applies to electrical circuits; it applies to electrical circuits; it states that the current through a states that the current through a conductor between two points is directly conductor between two points is directly proportional to the potential difference or proportional to the potential difference or voltage across the two points, and voltage across the two points, and inversely proportional to the resistance inversely proportional to the resistance between them.between them.

• The mathematical equation that describes The mathematical equation that describes this relationship is: V=R.Ithis relationship is: V=R.I

Types of resistorsTypes of resistors

Grouping of resistors:Grouping of resistors:

• Parallel grouping.Parallel grouping.

• Series grouping.Series grouping.

Parallel Grouping:Parallel Grouping:

1/Req = 1/ R1 + 1/R2 + 1/R3 + 1/R4 + ….

Series Connection:Series Connection:

•Req = R1 + R2 + R3 + R4 + ….

Our body resistanceOur body resistance

• If dry about 5ooooIf dry about 5ooooᾩ.ᾩ.• It is dangre to exposd to direct elctric It is dangre to exposd to direct elctric

current current