# 9.3 Resistance

27 April 2023
Unit 9.3 Resistance
1 / 44
Slide 1: Tekstslide
PhysicsSecondary EducationAge 12,13

In deze les zitten 44 slides, met interactieve quizzen, tekstslides en 1 video.

## Onderdelen in deze les

27 April 2023
Unit 9.3 Resistance

#### Slide 1 -Tekstslide

Content objectives
• I can explain the effect of resistance to current in a circuit.
• I can state the equation that links voltage, current, and resistance (Ohm's Law).
• I can use Ohm's law to calculate resistance from voltage and current.

#### Slide 2 -Tekstslide

What have I learned?
• Describe how current flows in a conductor.
• Describe the difference between a conductor and an insulator regarding current flow.
• What does the word resistance mean in everyday language?

#### Slide 4 -Video

Resistance
• a measure of how easy or difficult it is for electrons to move through a material
• Symbol: R
• measured in units called "ohms" or Ω

#### Slide 5 -Tekstslide

Which of the following is a conductor?
plastic
wood

#### Slide 6 -Poll

Which of the following has the lowest resistance?
copper
plastic
wood

#### Slide 7 -Poll

Example
• A 100 m length of copper can have a resistance of 0.5-1.0 Ω.
• A 1-cm length of plastic can have a resistance of 1000000000000 Ω.

#### Slide 8 -Tekstslide

What does resistance do?
A
slows down the flow of electrons
B
makes current higher

#### Slide 9 -Quizvraag

Why is the wire covered with plastic?

#### Slide 10 -Tekstslide

Conductors in light bulbs
• Some conductors are designed to have high resistance. WHY?

#### Slide 11 -Tekstslide

Conductors in light bulbs
• Some conductors are designed to have high resistance. WHY?
filament

#### Slide 12 -Tekstslide

As resistance makes it difficult for current to flow ____________.
the greater the resistance in a circuit
the lesser the resistance in a circuit

#### Slide 13 -Poll

The greater the resistance in a circuit, the __________ the current flow
smaller
bigger

low
high
easy

#### Slide 16 -Tekstslide

Ohm's Law
• Georg Simon Ohm
• link between voltage, current, and resistance
• resistance applies to many electrical components not only wires

#### Slide 17 -Tekstslide

Using an equation, what does Ohm's Law say?

#### Slide 18 -Tekstslide

Using an equation, what does Ohm's Law say?

#### Slide 19 -Open vraag

Resistors
• a type of electrical component designed to have a known resistance
• colours in these resistors for a code to show the resistance value in ohms.

#### Slide 21 -Tekstslide

26 April 2023
Unit 9.2 Current and Voltage in parallel circuits

#### Slide 22 -Tekstslide

What do I call these devices?

#### Slide 23 -Tekstslide

What do I call the devices shown?

#### Slide 24 -Open vraag

How are these devices connected in a circuit?
Ammeter -

Voltmeter -

#### Slide 25 -Tekstslide

Voltage in a SERIES circuit

#### Slide 26 -Tekstslide

Voltage in a SERIES circuit

#### Slide 27 -Tekstslide

Adding more components in a Series circuit

#### Slide 28 -Tekstslide

Adding more components in a Series circuit

#### Slide 29 -Tekstslide

Adding more components in a Series circuit

#### Slide 30 -Tekstslide

What happens to the current in a series circuit if you increase the number of cells?
A
current increases
B
current decreases

#### Slide 31 -Quizvraag

What happens to the voltage in a series circuit if you increase the number of cells?
A
Voltage increases across each component.
B
Voltage decreases in the battery.

#### Slide 32 -Quizvraag

Voltage in a PARALLEL circuit

#### Slide 33 -Tekstslide

What do you notice in these diagrams?

#### Slide 34 -Tekstslide

Adding more components in a Parallel circuit

#### Slide 35 -Tekstslide

Adding more components in a Parallel circuit

#### Slide 36 -Tekstslide

What happens to the supply voltage in a parallel circuit if you increase the number of cells?
A
supply voltage increases
B
supply voltage decreases

#### Slide 37 -Quizvraag

What happens to the voltage across each branch in a parallel circuit if you increase the number of cells?
A
voltage increases
B
voltage decreases

#### Slide 38 -Quizvraag

What happens to the current through the cell in a parallel circuit if you increase the number of cells?
A
current through the cell increases
B
current through the cell decreases

#### Slide 39 -Quizvraag

What happens to the current through each branch in a parallel circuit if you increase the number of cells?
A
current through each branch increases
B
current through each branch decreases

#### Slide 40 -Quizvraag

Practice Activity

voltage
parallel
series
current

#### Slide 42 -Sleepvraag

Classwork Activity

What's next?