Ohm’s LawOhm’s Law

This presentation is designed to give you the basic principles of Ohm’s

Law

Learning Objectives- Upon Learning Objectives- Upon completion of this lesson…completion of this lesson…

Students will know the various variables of Ohm’s Law and what they signify

Students will know the relationships of the variable

Students will know how to compute the missing variable given the other two

V= VoltageV= Voltage

Voltage is the amount of work done per unit of charge

Voltage is measured in Joules per CoulombIt is often thought of as the amount of

“energy” being appliedThe unit applied is “Volts/V”

I= CurrentI= Current

Current is the flow of electrical charge through a system

Current is measure in amperes, which is equivalent to 1 coulomb per second

The unit applied is “Amperes/Amps”

R=ResistanceR=Resistance

Resistance is the opposition to the pass of the electrical current.

Resistance is caused by objects such as lights or switches being applied to a circuit

Resistance is measured in ohmsThe unit applied is “Ohms/Ω”

Ohm’s LawOhm’s Law

Ohm’s LawOhm’s Law

Solving for “V”Solving for “V”

• Cover “V”• Remaining formula is “I x R”• Meaning as current or resistance increases

the voltage will increase• Giving voltage a direct relationship to the

other two variables

Ohm’s LawOhm’s Law

Solving for “I”Solving for “I”

• Cover “I”• Remaining formula is “V/R”• Meaning as voltage or resistance increases

the current will decrease• Giving current an inverse relationship to the

other two variables

Ohm’s LawOhm’s Law

Solving for “R”Solving for “R”

• Cover “R”• Remaining formula is “V/I”• Meaning as current or voltage increases the

resistance will decrease• Giving resistance an inverse relationship to

the other two variables

Practice ProblemPractice Problem

Ohm’s LawOhm’s Law

SolutionSolution

Ohm’s Law Basics RecapOhm’s Law Basics Recap

Voltage is directly related to current and resistance

Current and resistance are inversely related to the other variables

Use the pie chart to solve for missing variables in a circuit

Practice:Practice:With a partner fill in the missing values from the table.With a partner fill in the missing values from the table.

20 V 0.2 Amps ? Ω

120 V 5 Amps ? Ω

240 V ? Amps 4 Ω

? V 0.4 Amps 8 Ω

9 V ? Amps 0.3 Ω