# 9.8 How components affect the current

9.8 How components affect the current
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Slide 1: Tekstslide
ScienceMiddelbare schoolvmbo lwoo, vwoLeerjaar 2

In deze les zitten 26 slides, met interactieve quizzen en tekstslides.

## Onderdelen in deze les

9.8 How components affect the current

#### Slide 1 -Tekstslide

This lesson

• recap quiz
• What is voltage?
• What is resistance?
• Formulas Resistance and voltage

#### Slide 2 -Tekstslide

Learning goals

• You can explain what resistance is in your own words.
• You can explain what voltage is in your own words.
Know the formula of resistance and do calculations with it.
• You can describe the difference between how current is measured and how voltage is measured.

• You can describe how voltage gets divided over series and parallel circuits.

#### Slide 3 -Tekstslide

An iPhone charger uses a current of 0.08 ampere when connected to a European socket. With this current it takes an iPhone 12, 2 hours and 8 minutes to go from 0% to 100%. How much coulomb flew through the wire in this time?

A
576 C
B
0.224 C
C
614.5 C
D
96000 C

#### Slide 4 -Quizvraag

A current of 0,6 A flows out of the battery. What is the current flowing through each lamp?
A
0.2 A
B
0.6 A
C
0.3 A
D
1.2A

#### Slide 5 -Quizvraag

A current of 0,6 A flows out of the battery. What is the current flowing through each lamp?
A
0.2 A
B
0.6 A
C
0.3 A
D
1.2A

#### Slide 6 -Quizvraag

Current out battery = current component 1 = current component 2 =....
Series circuits
Current out battery = current branch 1 + current branch 2 +....
Parallel circuits

#### Slide 7 -Tekstslide

Resistance & voltage

#### Slide 8 -Tekstslide

What is resistance?
Resistance is the opposition to current flow.

#### Slide 9 -Tekstslide

What is voltage?

1.A force needed to make the charges flow in a circuit.

(also known as potential difference)

#### Slide 10 -Tekstslide

• What is the difference between how you connect an ammeter and a volt meter in a circuit?

• How does voltage get divided over series and paralel circuits?

#### Slide 11 -Tekstslide

• What is the difference between how you connect an ammeter and a volt meter in a circuit?
An ammeter gets connected in series while a volt meter gets connected parallel.

#### Slide 12 -Tekstslide

• How does voltage get divided over series and paralel circuits?
Series
Parallel
Voltage
Gets divided over the components
The same at every circuit loop.

#### Slide 13 -Tekstslide

Homework
• Read 9.8 + 9.9
• Do the yellow block exercises of 9.8 and work book
• Do the yellow block exercises of 9.9 and workbook

#### Slide 14 -Tekstslide

the brightness is normal with one lamp
With two lamps:  1. the lamps are dimmer
2. The value on the ammeter is halved.

Each component like lamp provides resistance to the flow of charge
What is Resistance: Resistance is the opposition to the flow of charge (electrons)

#### Slide 15 -Tekstslide

With two cells 1.the lamp is brighter and the value on the ammeter is twice that it was before.

#### Slide 16 -Tekstslide

Parallel circuit with two lamps.
1. Brightness is the same as one lamp.
2.Adding more lamps in parallel increases the current.

#### Slide 17 -Tekstslide

Parallel circuit with two cells

#### Slide 18 -Tekstslide

The current (I)  in the circuit depends on:
1. Voltage(V)
2. Resistance ( R)
I = V / R (Current = Voltage Divided by Resistance)

#### Slide 19 -Tekstslide

Formulas: resistance and voltage (Ohm's law)
I = V / R (Current = Voltage Divided by Resistance)
I is current measured in amperes and
V is voltage measured in volts.
R is resistance measured in ohms
Rearrenging the formula:
V = I x R (Voltage = Current multiplied by Resistance)
R = V / I (Resistance = Voltage divided by Current)

#### Slide 20 -Tekstslide

Resistance

Symbol: R

Unit: Ohm
Symbol for Ohm: Ω

Resistance is the opposition to current flow.
Examples:
• Resistance = 5 Ohm
• R = 5 Ω

#### Slide 21 -Tekstslide

Exercise 1
Find out the amount of current flowing through the electric heater having a voltage of 220 V and resistance is 10 Ω.

#### Slide 22 -Tekstslide

Find out the amount of current flowing through the electric heater having a voltage of 220 V and resistance is 10 Ω.

G:   V= 220 v , R= 10Ω.
A: I =?

F: I= V/R
C:  I= 220/10=22 A

#### Slide 23 -Tekstslide

Example 2
Find the resistance of an electrical circuit which has the voltage supply of 10 Volts and current of 0.005 A.

#### Slide 24 -Tekstslide

Find the resistance of an electrical circuit which has the voltage supply of 10 Volts and current of 0.005 A.

G: V=10 v    I= 0.005 A

A:  R = ?
F:   R= V/I
C:  R= 10/0.005 = 2000 Ω