6-2 Resistance (p 225)

• Natuurkunde
• Middelbare school
• havo
• Leerjaar 3

Resistance (6.2 p 225)

Pen, pencil, iPad, writingbook, calculator

Phones in the phone bag

Schoolbags in the cupboard

Lesson goals:

• Make calculations with Ohms law.

Differences in current...

All household appliances use a voltage of 230 V but still a kettle uses morge energy than for example a LED. The reason for this difference is resistance. 

A kettle has a higher resistance than a 

LED.

Resistance of a conductor

The greater the resistance, the more difficult it is for the current to pass through the conductor.

Formula:

R=​I​​U​​

R - Resistance 

(ohm)

U - Voltage 

(Volt)

I - Current 

(Ampére)

Ω

V

A

What is the symbol for voltage?

1. C
2. Q
3. U
4. I

If the voltage is 230V and the current is 300mA, what is the resistance?

1. 0,76 ohm
2. 767 ohm
3. 69 000 ohm
4. 69 ohm

If the resistance is 5 ohm and the voltage is 2V, what is then the magnitude of the current?

1. 2,5 A
2. 0,4 A
3. 10 A
4. 0,01 A

What is the voltage across a resistance (0,3 ohm) if the current through the resistor is 250 mA?

1. 75 V
2. 0,075 V
3. 833 V
4. 0,83 V

question 15 (p 229)

16 (p 229)

17 (p 229)

What did you
learn today?

Homework

Q 18 on p 230 (make the graph in your writingbook and the rest in the digital method)

Conclusion:

• Resistance - current passes through it with difficulty
• Formula

R - Resistance in Ohm

U - Voltage in volt

I - Current in Ampére

R=​I​​U​​