# H5.3a Seriecircuits TV3B

5.3a Seriescircuits
Connecting resistors
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Slide 1: Tekstslide
NatuurkundeMiddelbare schoolvwoLeerjaar 3

In deze les zitten 18 slides, met interactieve quizzen en tekstslides.

Lesduur is: 45 min

## Onderdelen in deze les

5.3a Seriescircuits
Connecting resistors

#### Slide 1 -Tekstslide

Last week
• (I,U)-diagram is a graph in which the current is plotted against the voltage.
• A resistor obeys Ohm's law, resistance is always constant.
• A light bulb does not, because the resistance of the filament increases as the wire heats up.

#### Slide 2 -Tekstslide

The package of an LED light bulb reads: 12 V/ 100 mA.
Calculate the resistance of the light bulb when it is lit at the correct voltage.

#### Slide 3 -Open vraag

Elaboration:
Given:
U = 12 V
I = 100 mA = 0,100 A

R = ?

Elaboration: R =      =              = 120 Ω
IU
0,10012

#### Slide 4 -Tekstslide

This lesson
Lesson goals:
• you know what a series circuits is.
• you can calculate the voltage across each resistor in a series circuit.
• you can calculate the equivalent resistance of the resistors in a series circuit.

Serie circuit
Parallel circuit
Mixed circuit

Serie circuit

#### Slide 7 -Tekstslide

Current
• rule: current flows from + to - (elektrons from - to +)
• The current is the same everywhere in a series circuit (because the current can only go through 1 'path')
• I = I1 = I2 = I3 = ...

serie circuits

#### Slide 8 -Tekstslide

Voltage
• The voltage divides among the various components in a series circuit.
• Utot = U1 + U2 + ...
serie circuits

#### Slide 9 -Tekstslide

Equivalent resistance
• more resistors in an circuit  --> bigger resistance
• Req = R1 + R2 + R3 + ...
• Req = equivalent resistance = the total resistance in Ω
serie circuits

#### Slide 10 -Tekstslide

=
10
Utot = U1 + U2 + ...
I = I1 = I2 = I3 = ...
R3 = U/I = 6/0.12 = 50Ω
R3 = R1 + R2
1,2 V
4,8 V
1,2 V
0,12 A
0,12 A
40
10

=

#### Slide 12 -Tekstslide

Circuitry Analysis
1. Simplify all parallel 'blocks'.
2. Calculate Req.
3. Calculate Isource.
4. Calculate the voltage across each 'block'.
5. Calculate the individual current through e.ach resistor

#### Slide 13 -Tekstslide

Exercise
Resistance (Ω)
Current (A)
Voltage (v)
R1
5000
R2
3300
R3
500
R4
100
Assignement: Complate the table shown on the bottom of this slide. Analyze the circuit according to the instructions given.
Req = R1 + R2 + R3 + .....
Isource = I1 = I2 = I3 =.....
Usource = U1 + U2 + U3......
Req = R1 + R2 + R3 + R4 = 5000+3300+500+100 = 8900Ω
Isource = Usource/Req = 24/8900 = 0,00269

Stap 2:
Req
Stap 3:
Isource
Stap 4:
U1...
U = I x R
U1 = 0,00269 x 5000 = 13,5 V
U2 = 0,00269 x 3300 = 8,9 V
U3 = 0,00269 x 500 = 1,35 V
U4 = 0,00269 x 100 = 0,27 V

#### Slide 14 -Tekstslide

Summary
• Current is the same everywhere in series circuit.
• The voltage distributes itself among the various components
• Equivalent resistance (Req) can be calculated by adding the resistances together.

#### Slide 15 -Tekstslide

Individuel assignment
Stap 2:
Calculate Req
Stap 3:
Calculate Isource
Stap 4:
Calculate the voltage across each 'block'.
Resistance (Ω)
Current (A)
Voltage (V)
R1
2000
R2
1470
R3
2200
R4
1850
Rtot = R1 + R2 + R3 + .....
Ibron = I1 = I2 = I3 =.....
Ubron = U1 + U2 + U3......
Homework: 1, 3, 4
Questions? Send in the chat or put your mic on.

#### Slide 16 -Tekstslide

Individuele Assignment

#### Slide 17 -Open vraag

Homework
5.3:  3ab, 4, 5, 6