2-4 Electricity in the home (2.3)

• Natuurkunde
• Middelbare school
• havo
• Leerjaar 2

Electricity in the home

(p. 70)

Stationary

- Writing book and iPad

- Pen, pencil and geotrianlge

- Calculator

Schoolbags in

the cupboard

Phones in the phone bag

Bluetooth 

- ON

- VPN off

Lesson goals:

• Explain how an electric circuit is connected in a house.
• Calculate the total current used in a house.
• Calcualte the total power used in a house.
• Explain what is meant with switch wire, neutral wire  

       and live wire.

• Explain the difference between overloading and 

       short circuit

Domestic electrical systems

• There is a network of electrical  

       wiring running through the walls.

• This usually splits into four circuits

     U = U₁ = U₂ = U₃ = U₄ = 230V

• Each group has its own circuit switch.
• you can disconnect a circuit from the power line with the circuit switch. This is useful for repairs.

groter power = greater current

Total power drawn:

P₁= 15W    P₂= 40W

P_tot=55W

I​total​​=I​1​​+I​2​​+I​3​​+I​4​​+...

P​total​​=P​1​​+P​2​​+P​3​​+...

P​tot​​=P​1​​+P​2​​+...

=U​1​​⋅I​1​​+U​2​​⋅I​2​​+...

P​tot​​=U⋅I​tot​​

Fasedraaden nuldraad

Brown - live wire

Blue - neutral wire

Brown 230V - Blue no voltage

From the light switch to the lamp there is a black wire

 - Swith wire: Only has a voltage if the switch is on

Overloading

The current in a circuit may not exceed 16 A. 

If it is more there is a fire danger

Too many appliances = overloading

As long as the total power of all 

apliances does not exceed 3,7kW, it is safe.

P​max​​=U⋅I​max​​

=230⋅16

=3680W

=3,7kW

Short circuit:

The resistance is too low.

This happens when the current can take a shortcut, therefore bypass the appliance. this results in a low resistance, and therefore in a high current.

 - short circuit: resistance is too

   low, and therefore the current is

   too high.

Why do washing machines often get their own circuit?

1. They use a high voltage
2. They use a high current
3. They work with water
4. It has a higher risk to short circuit

Why does a toaster NOT have its own group?

1. It draws a low power
2. It works on a low voltage

Now do question (p. 76)

IA

Now do Q 30 (p76)

What did you
learn today?

             Do the following

      31 (p. 76) and test yourself 2.3

ALS JE KLAAR BENT: Do the test yourself 2.1 and 2.2

Rules:

• Do the calculations in your book, answers digital
  



• Use your textbook when you get stuck
• No talking/ discussion
  


• What you dont finnish is homework