W17 Activity 1 - Ohm's Law

W17 Activity 1

Ohm's Law

By Nicholas Carrillo

Voltage differences cause electric charges to move

​

​How much charge moves through a wire per second is called electric current.

​

Units: Amps (A)​

​

​When you connect one end of a battery to the opposite end (+ to -), current will flow.

​

How much current will flow is based on if there is anything in between...like a light bulb!

​

​Things like lightbulbs have a resistance that limits current.

​

In general we call them resistors.

​

Units for resistance is Ohms (Ω)

​

Multiple Choice

Which best describes what voltage does in a circuit?

• Voltage differences cause electric charges to move through a circuit.

• Voltage differences polarize charge in a circuit

• Voltage differences cause lightbulbs to light up

Multiple Choice

What are the units for voltage?

• Volts (V)

• Amps (A)

• Ohms ( $$\Omega$$  )

Multiple Choice

The amount of electric charge flowing per second is known as...

• Electric Current

• Resistance

• Voltage

• Ohms

Multiple Choice

What are the units for electric current?

• Volts (V)

• Amps (A)

• Ohms ( $$\Omega$$  )

Multiple Choice

Which of the following best describes resistance?

• Resistance limits the amount of current flow

• Resistance enhances the amount of current flow

• Resistance pushes the electric charges back.

• Resistance pushes the electric charges forward.

Multiple Choice

What are the units for resistance?

• Volts (V)

• Amps (A)

• Ohms ( $$\Omega$$  )

The relationship between voltage, current, and resistance is:

​

V = I*R​

​

Ohm's Law​

​Ohm's Law tells us that if we want a lot of current, we need either a lot of voltage, little resistance, or some combination of both.

​

A 9V battery is connected across a lightbulb with 10Ω of resistance.

​

What is the current through the light bulb?

​

V = I*R

I = V/R

I = 9/10 = 0.9 A​

​

0.9A is going through the lightbulb​

1A of current is going through a light bulb with 20Ω or resistance.

​

What is the voltage across the light bulb?​

​

​V = I*R

V = 1*20

V = 20 V

​

20V are across the light​bulb

12V are put across a lightbulb, and a current of 2A flows through the light.

​

What is the resistance of the light bulb?

​

V = I*R

R = V/I

R = 12/2 = 6​Ω

​

​The lightbulb has a resistance of 6​Ω

​

​

Fill in the Blank

Write down the equation for ohm's law (No Spaces)

Fill in the Blank

A 12V battery is connected across a lightbulb with 10Ω of resistance.

​

What is the current through the light bulb?

Units: [Amps]

Fill in the Blank

3A of current is going through a light bulb with 10Ω or resistance.

​

What is the voltage across the light bulb?​

Units: [Volts]

Fill in the Blank

120V are put across a lightbulb, and a current of 3A flows through the light.

​

What is the resistance of the light bulb?

​Units: [Ohms ]

Summary