4.2 Voltage sources

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• Middelbare school
• havo, vwo
• Leerjaar 2

4.2 Voltage sources

Recap

Voltage

Batteries

Connecting batteries together

Safe and unsafe voltages

Which of the following is a good conductor of electricity?

1. Copper
2. Wood
3. Rubber
4. Glass

Which material is an insulator?

1. Brass
2. Aluminum
3. Iron
4. Plastic

quizizz.com

What is voltage?

Voltage is the force that pushes charges (electrones) to move around a circuit. 

In other words, it is the amount of energy given to the components in a circuit from the electrons passing through the wire. 

Voltage source

A battery always states what voltages it supplies.

A battery supplies electrical energy. 

The current tells you how many charged particles flow past every second.

The voltage tells you how much electrical energy each particle is carrying.

Measuring

Voltage is measured in volts using voltmeter (V)

Current is measured in ampère using a ammeter (A)

Voltage sources

Today's topics: 

Solar cell

dynamo

Cell

Battery

A special V-source

A capacitor stores electrical energy

When you let the charge out, the voltage gets reduced, until it is empty again.

A capacitor is often used to protect components against rapid voltage changes.

I and V

You can compare the transport of electrical energy to the transport of petrol.

Current = trucks

Voltage = petrol

Or a central heating

current = water, voltage = heath

Voltage

Voltage (U) is measured in Volts (V).

So a AA battery:

U = 1.5 V

Connecting batteries

If you connect batteries in series (behind each other), you can add their voltages together.

Voltages

mains voltage = 230 V

Safe voltages = voltages untill 24 V

You can convert the mains voltage with a transformer.

Study Skills 7 on page 309

Chemical voltage sources

Batteries are chemical voltage sources because the voltage is generated by chemical reactions.

In rechargeable batteries you can make this reaction go in the opposite direction (recharge the battery). 

Batteries are small-scale chemical waste.

Concluding:

Recap

Voltage

Batteries

Connecting batteries together

Safe and unsafe voltages

Thanks and now you may: 

Read 4.2 (if necessary)

Do assignments: 4 to 7

Hw: 4.2: 1 to 7

Good luck!

If you have any questions, please ask. 

Electrical circuit

The link on the next page allows you to simulate an electrical circuit in a digital way. 

Create an electrical circuit consisting of:

- 2 bulbs

- 1 battery of 1,5V

phet.colorado.edu