2-5 Calculations (2.2)

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

Calculations (p. 71)

What you need:

- Textbook, writingbook, iPad

- Pen, pencil, geotriangle

- Calculator

Schoolbags in the cuboard

Phones in the phonebag

Bluetooth 

- ON

- VPN off

    Lesson today:

- Lesson goals (5 min)

- Content (15 min)

- Work by yourself 

     (20 min)

- Corrections (8 min)

- Conclusion(2 min)

                       Lesson goals:

- Calculate the voltage of batteries in series and in parallel. 

- Distinguish between parallel en series circuits. 

- Explain what the difference is between thick and thin batteries. 

- Explain what adapters do.

Increasing the voltage

If you need a higher voltage, you connect batteries in sereis 

(+ of one battery connected to the - of the other)

3 batteries of 1,5 V = 4,5 V

One battery of 9 V is made up of 6 small 1,5V batteries.

Calculations:

An accumulator with a voltage of 14,4 V is made up of 3,6V batteries.  How many batteries are connected in sereis?

14,4:3,6 = 4

Series connection

- Nett voltage 3 V

- Advantage: higher voltage

Parallel connection

- Nett voltage 1,5 V

- Advantage: Lasts longer

EXTRA content

Thick and thin batteries

All batteries are 1,5 V

Thick batteries have more

chemicals, and therefore last

longer.

Capacity:

• The amount of electricity that is stored in a battery.
  
• The unit is mAh
  
• 2 000 mAh battery lasts twice as 

       long as a 1 000 mAh battery  

      

Extra content:

Adapter:

• converts 230 V mains to the voltage required 
  
• and it converts alternating current into direct current
  

Q - Which burns brighter?

1. 12 V 1A
2. 12V 2A
3. same brightness
4. One can't tell

What is the total voltage?

1. 0V
2. 6V
3. 18V
4. 36V

What is the total voltage?

1. 0V
2. 12V
3. 48V

What is the total voltage?

1. 0V
2. 6V
3. 12V
4. 24V

What benefit is there to a thick battery?

1. It lasts longer
2. It gives a higher voltage
3. It provides more current
4. It fits into the richt appliances

Which will last longer?

1. 0,1mA
2. 0,09 mA

Batteries connected in series, provide a higher current than when they are used separately.

1. True
2. False

A wind turbine has a big dynamo.

1. True
2. False

Rechargeable batteries get finished more quickly that non rechargeable batteries.

1. True
2. False

An adapter converts direct current to alternating current.

1. True
2. False

A battery with a higher capacity lasts longer.

1. True
2. False

A battery with a higher capacity provides a higher voltage.

1. True
2. False

Now do  30 up to 36 (p. 72)

WHEN YOU ARE DONE: 

RULES:

• Write in your writingbook
  



• Use: Your textbook
• No discussion
  


• In 20 minutes we will discuss the answers
  

make the drawings in 33 and 34 in pencil and with a ruler!

Conclusion:

• The voltage of the battereis in sereis we add up to get the total voltage. 
• If batteries are connected in parallel, the voltage remains the same. 
• Bigger batteries have a higher capacity.