6-4 Bodily resistance and resistance in series (6.2)

Bodily resistance and resistance in series (p 228)




Stationary
- Writingbook
- Pen and pencil
- Calculator
- iPad

Mark
- NO


Lessonup
- YES
schoolbag in
the cupboard
Phones in the phonebag
1 / 26
volgende
Slide 1: Tekstslide
NatuurkundeMiddelbare schoolhavoLeerjaar 3

In deze les zitten 26 slides, met interactieve quizzen en tekstslides.

time-iconLesduur is: 50 min

Onderdelen in deze les

Bodily resistance and resistance in series (p 228)




Stationary
- Writingbook
- Pen and pencil
- Calculator
- iPad

Mark
- NO


Lessonup
- YES
schoolbag in
the cupboard
Phones in the phonebag

Slide 1 - Tekstslide

Lesson goals:
- Explain how bodily resistance 
influences the current through 
your body during an electric shock.
- Make calculations with the current,
voltage and resistance in a series circuit.

Slide 2 - Tekstslide

Size of the current?
- Depends on the voltage and
resistance.
- Total bodily resistace =
contact resistance + body resistance

Slide 3 - Tekstslide

Body as a conductor
- The body is a good conductor
- Body resistance is between 100 and 500 ohm
- Contact resistance is about 100 k ohm if your skin is dry
- With a wet skin - drops to 1 000 ohm

Slide 4 - Tekstslide

Correct voltage for the perfect lightbulb
A lightbulb that works perfectly
at 6V could be damaged at 9V.

Say you have a battery of 9V, 
but a lightbulb of 6V, could you then still conenct the lightbulb to this battery?

Slide 5 - Tekstslide

6V lamp and 9V powersource
Then you have to increase the resistacne 
to use the 9V battery.

BECAUSE - If the resistance increases, the current will decrease.

Slide 6 - Tekstslide

More resistances in series
The more resistances you connect in sereis the greater the total resistance will be. Rtot = R1 + R2 + R3



SO Rtot = 250 + 550 + 1 000 = 1 800 ohm
Total resistance

Slide 7 - Tekstslide

Current and voltage in a series circuit 
The current in a series circuit
is the same everywhere...

.... BUT the voltage is shared
accrosst he circuit components

Slide 8 - Tekstslide

What if the resistance are different ...
U1=IR1
U2=IR2
U3=IR3
R1
R2
R3

Slide 9 - Tekstslide

What is the total resistance?
A
9
B
3
C
12
D
11

Slide 10 - Quizvraag

How does the
current at A1 compare to the current at A2?
DIRECTION OF CURRENT
A
A1 > A2
B
A1 = A2
C
A1 < A2
D
One could not say

Slide 11 - Quizvraag

What is the voltage in U2?
A
3V
B
6V
C
9V
D
12V

Slide 12 - Quizvraag

What is the voltage in U?
A
3V
B
6V
C
9V
D
12V

Slide 13 - Quizvraag

What is the
current?
A
2 A
B
3A
C
5 A
D
1,2 A

Slide 14 - Quizvraag

What is the current?
A
7 A
B
4 A
C
3 A
D
1,2 A

Slide 15 - Quizvraag

What is the
magnitude of the
unknown resistance?
A
1
B
2
C
3
D
4

Slide 16 - Quizvraag

Slide 17 - Tekstslide

Slide 18 - Tekstslide

Do question 27 (p 238)
timer
3:00

Slide 19 - Tekstslide

Slide 20 - Tekstslide

Do question 28 (p 238)
timer
4:00

Slide 21 - Tekstslide

Slide 22 - Tekstslide

Do question 29 (p 238)
timer
4:00

Slide 23 - Tekstslide

Slide 24 - Tekstslide

What did you
learn today?

Slide 25 - Woordweb

You could do Q 22 and 23 in the digital method (p 231)

This is on bodily resistance

NEXT LESSON - Parallel circuits
timer
10:00

Slide 26 - Tekstslide