2-10 Safety in the house (2.4)

• Natuurkunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Online lesson etiquette

1. Be on time

2. Have book, pens etc ready beside you.

3. Camera on, microphone off.

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5. Chat is only for lesson material.

                       Lesson goals:

- Distinguish between a circuit overload and a short circuit.

- Explain why an extention cord must be rolled out before use.

- Explain what the purpose of a fuse is.

Fire

• When more appliances are connected to a socket,  a greater current will be used (circuit overload).
• If the current is more than 16 A - it becomes a fire hazard.
• The input cable becomes too hot and could catch fire.

Short circuit

When the current does not go through the appliance.

The current returns to the socket, without moving through the appliance.

Extention cord

Must be fully unrolled, otherwise the heat can not escape.

P_max

P_min

Fuses

An electric installation is protected from short circuits and overloads.  

Fuse

- Electronic

- Melt (ceramic) fuses

Short circuit or circuit overload?

1. short circuit
2. circuit overload

short circuit or circuit overload?

1. short circuit
2. circuit overload

When more appliances are connected to one electric socket, the current in each appliance becomes less.

1. true
2. false

When too many appliances are connected to a socket, the fuse will switch the current off.

1. true
2. false

The electric wires going to a light fitting, heat up a bit when in use.

1. true
2. false

Due to the electricity being split over groups in an electric installation, more appliances can be connected.

1. true
2. false

Houses are equipped with fuses to protect it from short circuits and overloads.

1. true
2. false

Now do  63 up to 65 (p. 88)

RULES:

• Write in your writingbook
  



• Use: Your textbook
• question 64, look at the table on p82.


• In 8 minutes we will discuss the answers