2 YR2_T2_LSN6 2.3

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Topic 2.3 Electricity
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Slide 1: Slide
ScienceMiddelbare schoolhavo, vwoLeerjaar 2

This lesson contains 39 slides, with interactive quizzes, text slides and 1 video.

time-iconLesson duration is: 45 min

Items in this lesson

YR2_T2_LSN6
Topic 2.3 Electricity

Slide 1 - Slide

Planning for today
  • Topic 2.3 Electricity
  • Test Topic 1 review
  • Bean Project

Slide 2 - Slide

Learning goals 2.3
I can…
  • Explain what electrical energy is made of.
  • Explain what current is, along with its unit of measurement.
  • Explain what voltage is, along with its unit of measurement.

Slide 3 - Slide

Key words
Electricity
Electrons
Electrical current (I)
Ampères (A)
Voltage (U)
Volts (V)
Voltage source
Power (P)
Watt (W)
Energy

Slide 4 - Slide

Slide 5 - Video

What is electricity?
Electricity is caused by the flow of electrons moving through a conducting material
  • Those electrons go from the power source to the device
  • In the appliance they leave their energy behind
  • They go back to the power source to be charged.

Slide 6 - Slide

Slide 7 - Slide

Electric wire






The plastic around the wire is an insulator (wire insulation)
The coper wire is a conductor (stripped wire)

Slide 8 - Slide

Voltage
 Voltage (U) is how much electrical energy each electron is carrying. 
 
Measured in Volts (V) with a voltmeter

Slide 9 - Slide

Current
A current (I) is how many electrons flow past every second.
 
Measured in Amps (A) with an "ammeter" (amperemeter)

Slide 10 - Slide

Voltage 
The power outlet has a voltage of 230V 
  • This can be dangerous and even deadly

24V is the safe limit  

Transformers raise/lower voltage



Slide 11 - Slide

Power
Power (P) is the amount of electrical energy used per second by a device.

Measured in Watts (W)

Watts is also J/s (joules per second)

Slide 12 - Slide

Calculate Power
Power can be calculated with the formula: P = U x I 

P for Power (in W = Watt)
U for Voltage (in V = Volt)
I for current (in A = Ampere)

Slide 13 - Slide

Energy consumption
All electrical devices use energy  → energy consumption

The amount of energy can be calculated with the formula:  E = P · t

E = Energy (in J = Joules)
P = Power (in W = Watt)
t = time (in s = seconds)

Slide 14 - Slide

Question 1
A device has a battery of 12V. There is a current going through the devies of 5A. What is the power (P) of this devies?


Slide 15 - Slide

Calculation 1
A device has a battery of 12V. There is a current going through the devies of 5A. What is the power (P) of this devies?
Answer:
P = U x I

Slide 16 - Slide

Calculation 1
A device has a battery of 12V. There is a current going through the devies of 5A. What is the power (P) of this devies?
Answer:
P = U x I
U = 12 V
 I = 5 A


Slide 17 - Slide

Calculation 1
A device has a battery of 12V. There is a current going through the devies of 5A. What is the power (P) of this devies?
Answer:
P = U x I
U = 12 V
 I = 5 A

P = 12V x 5A = 60W

Slide 18 - Slide

Question 2
A telephone has a 15V battery. Its power in low energy mode is 45W.
What is the current in the telephone?

Slide 19 - Slide

Calculation 2
A telephone has a 15V battery. Its power in low energy mode is 45W.
What is the current in the telephone?
Answer:
P = U x I    

Slide 20 - Slide

Calculation 2
A telephone has a 15V battery. Its power in low energy mode is 45W.
What is the current in the telephone?
Answer:
P = U x I    -> I = P / U

Slide 21 - Slide

Calculation 2
A telephone has a 15V battery. Its power in low energy mode is 45W.
What is the current in the telephone?
Answer:
P = U x I    -> I = P / U
U = 15 V
P = 45 W


Slide 22 - Slide

Calculation 2
A telephone has a 15V battery. Its power in low energy mode is 45W.
What is the current in the telephone?
Answer:
P = U x I    -> I = P / U
U = 15 V
P = 45 W

I = P / U = 45W / 15V = 3A

Slide 23 - Slide

Question 3
An electric kettle using a current of 2,22 A takes 1 minute and 24 seconds to boil the water.

Calculate the energy consumption of the kettle in kJ.


Slide 24 - Slide

Calculation 3
An electric kettle using a current of 2,22 A takes 1 minute and 24 seconds to boil the water. Calculate the energy consumption of the kettle in kJ.
Answer:
  • U = 230 V (from the socket); I = 2,22A

Slide 25 - Slide

Calculation 3
An electric kettle using a current of 2,22 A takes 1 minute and 24 seconds to boil the water. Calculate the energy consumption of the kettle in kJ.
Answer:
  • U = 230 V (from the socket); I = 2,22A
  • P = U x I = 230 x 2,22 = 510,6 W  
  • t = 60 + 24 = 84 s

Slide 26 - Slide

Calculation 3
An electric kettle using a current of 2,22 A takes 1 minute and 24 seconds to boil the water. Calculate the energy consumption of the kettle in kJ.
Answer:
  • U = 230 V (from the socket); I = 2,22A
  • P = U x I = 230 x 2,22 = 510,6 W  
  • t = 60 + 24 = 84 s
E = P x t
E = 510,6 x 84
P = 42 890 J = 42,9 kJ

Slide 27 - Slide

Calculation 3
An electric kettle using a current of 2,22 A takes 1 minute and 24 seconds to boil the water. Calculate the energy consumption of the kettle in kJ.
Answer:
  • U = 230 V (from the socket); I = 2,22A
  • P = U x I = 230 x 2,22 = 510,6 W  
  • t = 60 + 24 = 84 s
E = P x t
E = 510,6 x 84
P = 42 890 J = 42,9 kJ

Slide 28 - Slide

Calculation 3
An electric kettle using a current of 2,22 A takes 1 minute and 24 seconds to boil the water. Calculate the energy consumption of the kettle in kJ.
Answer:
  • U = 230 V (from the socket); I = 2,22A
  • P = U x I = 230 x 2,22 = 510,6 W  
  • t = 60 + 24 = 84 s
E = P x t

Slide 29 - Slide

What is an insulator?
A
A material that does not conduct electricity
B
A material that conducts electricity
C
A clamp to connect two electric wires
D
An electric source

Slide 30 - Quiz

There is a electrical current when...
A
the circuit is closed
B
when there is a electric source
C
when the wires are conductors
D
all three need to be true

Slide 31 - Quiz

Energy
Power
Time
Voltage
Current
I
P
U
E
t

Slide 32 - Drag question

What part of an atom makes it possible for electrical energy to travel?
A
Proton
B
Nucleon
C
Muon
D
Electron

Slide 33 - Quiz

The formula is P = U x I
Which of these is also correct?
A
U = I / P
B
U = P x I
C
U = P / I
D
U = P + I

Slide 34 - Quiz

What is the Voltage of a power outlet in a house?
A
360 V
B
12 V
C
230 V
D
1500 V

Slide 35 - Quiz

Slide 36 - Slide

Slide 37 - Link

Assignment 
Make the following circuits work in the app: "Inleiding"

  • let a lightbulb burn with a battery
  • let a lightbulb burn with a battery and a switch
  • let 2 lightbulbs burn with a battery and a switch
timer
8:00

Slide 38 - Slide

Homework
  • Read Topic 2.3 (p. 70-73)
  • Complete the exercise of Topic 2.3 (p.74-77)
  • Study the glossary of Topic 2.3 on StudyGo.

Slide 39 - Slide