Ohm's Law

Ohm's Law

Discovered by George Simon Ohm

It is composed of these three components.

Voltage

• The force motivating charge carriers to “flow” in a circuit is called voltage.

• Symbol used is V or E

• Unit of Measurement: Volts or V

Multiple Choice

How do we measure Voltage?

• Ω (Ohms)

• V (Volts)

• A (Amps)

• W (Watts)

Multiple Choice

What is the symbol used for Voltage?

• Ω

• A

• V

• C

Current

• Continuous movement of electric charge through the conductors of a circuit.

• Referred to in terms of “flow,” just like the flow of a liquid through a hollow pipe.

• Symbol used is I

• Unit of Measurement in Ampere (Amp) or A

Multiple Choice

What is the symbol used for Current?

• Ω

• A

• V

• I

Multiple Choice

How do we measure Current?

• Ω (Ohms)

• V (Volts)

• A (Amps)

• W (Watts)

Resistance

• Current tends to move through the conductors with some degree of friction, or opposition to motion

• Symbol is R

• Unit of Measurement is Ohm

• 
  

Multiple Choice

How do we measure Resistance?

• Ω (Ohms)

• V (Volts)

• A (Amps)

• W (Watts)

Multiple Choice

What is the symbol used for Resistance?

• O

• R

• I

• V

Multiple Choice

What word means how the electrons flow.

• Current

• Voltage

• Resistance

• Power

Multiple Choice

What word means how hard it is for electrons to flow through.

• Current

• Voltage

• Resistance

• Power

Multiple Choice

What word means how much energy is given to / removed from the electrons.

• Current

• Voltage

• Resistance

• Power

Solving Ohm's Law

A circuit contains two 4 volt batteries and a bulb with a resistance of 2 Ohms. Calculate the current.

Given:

Volts = 4 V

Resistance = 2 Ohms

Current= ?

Open Ended

Given:

V= 4 V
R= 2 Ohms
C= ?

Formula:

 $C=\ V\ \div R$  

 $C=\ 4\div2$ 
 $C=?$   

What is the voltage of a circuit with 11 Amps of current and toaster with 8 Ohms of resistance?

Given:

Resistance = 8 Ohms

Current= 11 Amps

Volts = ?

Multiple Choice

What is the formula that we are going to use?

Open Ended

Given:

R= 8 Ohms
C= 11 Amp
V= ?
Formula:

 $V=\ R\times C$  

 $V=\ 8\ \times11$ 
 $V=?$   

How many Ohms of resistance must be present in a circuit that has 90 Volts and a current of 15 Amps?

Enumerate the given on the next question.

Multiple Choice

What is being asked?

• Find the Volts

• Find the Resistance

• Find the Current

Open Ended

In the problem "How many ohms of resistance must be present in a circuit that has 90 volts and a current of 15 amps?"

What is the value of the Current?

Open Ended

In the problem "How many ohms of resistance must be present in a circuit that has 90 volts and a current of 15 amps?"

What is the value of the Voltage?

Multiple Choice

What is the formula that we are going to use?

Open Ended

Given:

V= 90 V
C= 15 A
R= ?

Formula:

 $R=\ V\ \div C$  

 $R=\ 90V\ \div15A$ 
 $R=?$   

Try to solve for the following:

Open Ended

If the battery produced 120 Volts and what would be the current flow be for a 6 Ohm resistor?

Open Ended

What resistance is needed to cause a 50A current flow because of a 250V battery?

Open Ended

What voltage is needed to cause a 22A current flow through a 5Ω resistor?