Science year 2.3: Electricity

Welcome back
Hopefully you had a good vacation
Continue with topic 2: Energy in the world
Inhalers make today an appointment with me
Next week different timetable
1: on Monday 9.00-9.45
2: on Wednesday 11.00 - 12.30 
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Slide 1: Slide
ScienceMiddelbare schoolhavoLeerjaar 2

This lesson contains 31 slides, with interactive quizzes, text slides and 1 video.

Items in this lesson

Welcome back
Hopefully you had a good vacation
Continue with topic 2: Energy in the world
Inhalers make today an appointment with me
Next week different timetable
1: on Monday 9.00-9.45
2: on Wednesday 11.00 - 12.30 

Slide 1 - Slide

Today
Reviewing 2.1 and 2.2

2.3 about electricity

Lesson up

Making exercises from the book and the brown bean project 

Slide 2 - Slide

Which types of energy do you know?

Slide 3 - Mind map

conduction is heat transfer through...
A
solid materials
B
fluids and gasses
C
nothing
D
glass

Slide 4 - Quiz

What is a conductor
A
material that prevents heat from traveling
B
material that is very hot
C
material that lets heat travel easily
D
somebody that works in a tram

Slide 5 - Quiz

What is a catalyst?
A
something that makes substances burn
B
something that prevents materials to burn
C
something that increases the ignition energy
D
something that lowers the ignition energy

Slide 6 - Quiz

Learning goals
What is electrical energy made of
What is current, and what unit do we use for it
What is voltage, and what unit do we use for it
Calculate the power a devies uses with the formula P=U.I
Calculate the Energy a devies uses with the formula E=P.t
how energy consumption depends on power and time of use 

Slide 7 - Slide

Name different sources of electricity

Slide 8 - Mind map

1

Slide 9 - Video

02:33
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
a electric source

Slide 10 - Quiz

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 11 - Slide

Slide 12 - Slide

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

Slide 13 - Slide

Slide 14 - Link

Assignment 
Make the following circuits work in the applet

- 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

Slide 15 - Slide

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 16 - Quiz

Current 
How many electrons flow past every second.
 
Measured in Amps (A) 
with an am-meter

Slide 17 - Slide

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

Slide 18 - Slide

How much voltage is in an electric socket at your home?

Slide 19 - Mind map

Voltage 
The mains socket has a voltage of 230V 
This can be dangerous and even deadly

24V is the safe limit  

Transformers raise/lower voltage



Slide 20 - Slide

Power
The power of a devies is the amount of energy is uses every second.

The power is measured in Watts (W)
Watts is also J/s (joules per second)

Slide 21 - Slide

Power
Power can be calculated with the formula:

P = U x I 

P for Power (in W)
U for Voltage (in V)
I for current (in A)

Slide 22 - Slide

A devies has a battery of 12 V. There is a current going through the devies of 5 A. What is the power of this devies?

Slide 23 - Open question

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

Slide 24 - Quiz

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

Slide 25 - Open question

Energy
Energy consumption is the amount of energy a devies uses during a certain time period.

1. Depends on the power of the devies  
2. Depends on the time the devies is on.

E = P x t

Slide 26 - Slide

A water boiler takes 3 minutes to heat the water. It has a power of 2000 W.
How much energy did the boiler use.
A
6000 J
B
667 J
C
0,015 J
D
360000 J

Slide 27 - Quiz

Energy
Power
Time
Voltage
current
I
P
U
E
t

Slide 28 - Drag question

J
W
s
V
A
I
P
U
E
t

Slide 29 - Drag question

Now you should know
What electrical energy is made of
What current is, and what unit do we use for it
What voltage is, and what unit do we use for it
How to calculate the power a devies using the formula P=U.I
How to calculate the Energy a devies using the formula E=P.t
How energy consumption depends on power and time of use 

Slide 30 - Slide

For next time
Make exercises of 2.3

If you have trouble making a question, write it down and ask about it in the next lesson.

Hand it in on classroom
(no homework done means no entrance)

Slide 31 - Slide